Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
How To Calculate The Length Of Menstrual Cycle?
Question: If your period is 28 days and your 3 days late. Will your next period be 28 days or will it be 25 days? I would think ovulation would fix itself and your next cycle may be a little shorter?
Brief Answer:
Your cycle should go back to normal next month
Detailed Answer:
Hello, and I can help you today.
In a normal menstrual cycle, the length of your cycle depends on what day you ovulate. Your period will come 2 weeks after you ovulate- so when your period is late, it usually means you ovulated late that month. The cycle should reset itself to normal the following month, which in a 28 day cycle means you will get your next period 28 days after the late period began. Your ovulation will not come earlier the next month to make up for the lost time.
Having your period come later or skip happens every once and a while to many women from stress, schedule changes and weight changes. If your cycle remains irregular for more than 6 months I recommend you see a GYN doctor for evaluation.
I hope I adequately answered your question and that this information was helpful.
Best wishes, Dr. Brown
Your cycle should go back to normal next month
Detailed Answer:
Hello, and I can help you today.
In a normal menstrual cycle, the length of your cycle depends on what day you ovulate. Your period will come 2 weeks after you ovulate- so when your period is late, it usually means you ovulated late that month. The cycle should reset itself to normal the following month, which in a 28 day cycle means you will get your next period 28 days after the late period began. Your ovulation will not come earlier the next month to make up for the lost time.
Having your period come later or skip happens every once and a while to many women from stress, schedule changes and weight changes. If your cycle remains irregular for more than 6 months I recommend you see a GYN doctor for evaluation.
I hope I adequately answered your question and that this information was helpful.
Best wishes, Dr. Brown
Above answer was peer-reviewed by :
Dr. Raju A.T
Okay thank you. The reason I ask is I'm pregnant and my period before was late by about 4 days. I was with 2 men and one ejaculAted in me on the 18 20 and 21 the second guy did not on the 23 24 26. My due date is October 18th which means the second guy is prob the dad but those days are so close I have to get a DNA test
Brief Answer:
I agree those dates are too close to guarantee paternity
Detailed Answer:
Hello again, and I am sorry for your situation.
It is also true that both the ovulated egg and the sperm can float around inside you for up to 72 hours before they come together so your actual conception can even be 5 days off from what you would expect.
I hope everything works out, and if you need anything else please do not hesitate to contact me.
I agree those dates are too close to guarantee paternity
Detailed Answer:
Hello again, and I am sorry for your situation.
It is also true that both the ovulated egg and the sperm can float around inside you for up to 72 hours before they come together so your actual conception can even be 5 days off from what you would expect.
I hope everything works out, and if you need anything else please do not hesitate to contact me.
Above answer was peer-reviewed by :
Dr. Raju A.T
So I could have ovulated on the 21 or 22nd?
Brief Answer:
I need to know the first day of your last period
Detailed Answer:
I am sorry- please give me the first day of your last period? I need this information to figure out when your ovulation might have occurred.
I need to know the first day of your last period
Detailed Answer:
I am sorry- please give me the first day of your last period? I need this information to figure out when your ovulation might have occurred.
Above answer was peer-reviewed by :
Dr. Raju A.T
My period was 3 days late and Started January 10th. I dont know if its possible to get pregnant without an ejaculation. But the date points to guy number 2. But guy 1 ejaculated in me during my fertile period obviously. I'm currently a little past 32 weeks. I took 25miu urine test on Feb 2nd but the conception date was January 25th I didn't think it would come back positive that early, which is another reason I thought guy number one was the father. That exactly 2 weeks from being with him if at all possible could you tell me who is more likely the father other than the date it realm sounds like guy number 1 is
Brief Answer:
Based on my calculation your due date Is different
Detailed Answer:
Based on my calculations, with the conception window you describe, both men could have fathered this child, however if one of the men did not ejaculate inside you it is much less likely. I also believe from using the first day of your last period to calculate your due date you should be due around October 16th, which leaves a window for conception between January 15-25th. I wish I could be more specific for you but unless you had a very early ultrasound for the pregnancy, that is the estimated date window where conception should have occurred if you have a 28 day cycle.
I wish you the best for the rest of your pregnancy and if you have any further questions feel free to contact me.
Sincerely, Dr. Brown
Based on my calculation your due date Is different
Detailed Answer:
Based on my calculations, with the conception window you describe, both men could have fathered this child, however if one of the men did not ejaculate inside you it is much less likely. I also believe from using the first day of your last period to calculate your due date you should be due around October 16th, which leaves a window for conception between January 15-25th. I wish I could be more specific for you but unless you had a very early ultrasound for the pregnancy, that is the estimated date window where conception should have occurred if you have a 28 day cycle.
I wish you the best for the rest of your pregnancy and if you have any further questions feel free to contact me.
Sincerely, Dr. Brown
Above answer was peer-reviewed by :
Dr. Raju A.T
My first ultrasound I had a 6 weeks 4 days. That's where I got conception date and due date. I was already developing a little baby bump. I do have a history of being irregular but the past 10 months or so had been regular. October 16 is not a big difference. Doctor said even that early the machine still has an error of +/-7 days. I just got to go with the DNA test but you helped out a whole bunch sound like to me you are also leaning towards guy 1. When i went back April 9th I read 12 weeks 4 days. Then they took me in for 3 D ultrasound ultrasound and I was closer to 14 weeks which is a bit of a difference ever since this the measurements have been consistent hints why I'm 32 weeks and a couple days. If that's right guy number 1 is deff the father. Also when I found out I went in the next day and they couldn't see anything on the ultrasound but confirmed my pregnancy they said I was 2-3 weeks most likely and I just counted back and that was when I was with guy number 1
Brief Answer:
Your ultrasound is the most accurate determination
Detailed Answer:
Hello again and thank you for the information.
An early ultrasound is the most accurate for dating the pregnancy- as the fetus gets larger the margin of error goes up- so your 6 week ultrasound is the most reliable piece of information we have to figure out the conception date. I would agree with the due date and conception date they told you at that time which I think is the one you say is the time you were with your first partner.
I hope this was helpful again and good luck with the rest of your pregnancy.
Your ultrasound is the most accurate determination
Detailed Answer:
Hello again and thank you for the information.
An early ultrasound is the most accurate for dating the pregnancy- as the fetus gets larger the margin of error goes up- so your 6 week ultrasound is the most reliable piece of information we have to figure out the conception date. I would agree with the due date and conception date they told you at that time which I think is the one you say is the time you were with your first partner.
I hope this was helpful again and good luck with the rest of your pregnancy.
Above answer was peer-reviewed by :
Dr. Raju A.T
No the 25th I was with the second guy but I was with the first guy 3 days earlier. I read the earlier the more accurate. But when I got to my actually doctor she changed my weeks by about a week. Even if the first ones right the first guy can still easily be the father. The lady at the clinic just asked about my period and that was all. And the ultrasound said January 25th. When I got to my actually doctor she basically told me the either measured to early or measured wrong. Its crazy I know. At 19 weeks i found at it was a girl and the conception date on that was january 21st which I was with guy number 1. As you see regardless of anything DNA test is the only way. I guess its more likely guy number 1 baby. I doubt I would know I was pregnant 8 days later as I could tell I was bloating
Brief Answer:
You change due date if It is more than 7 days off from your LMP
Detailed Answer:
Because of the margin of error, what we use to most accurately date a pregnancy is the ultrasound if it agrees with what date we would expect based on the patient's LMP (last menstrual period) within 1 week. So that makes sense if your OB changed your due date based on the ultrasound saying you're already 32 weeks.
Anyway you will need the test in the end for sure. Let me know if you need anything else.
You change due date if It is more than 7 days off from your LMP
Detailed Answer:
Because of the margin of error, what we use to most accurately date a pregnancy is the ultrasound if it agrees with what date we would expect based on the patient's LMP (last menstrual period) within 1 week. So that makes sense if your OB changed your due date based on the ultrasound saying you're already 32 weeks.
Anyway you will need the test in the end for sure. Let me know if you need anything else.
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj
Thank you, I read up on pregnancy test I took I took it 6 days before period was due and got 4 positives in a row! I had to be more than 8 days pregnant? Maybe my cycles were acting up. But I'm almost certain I was pregnant before January 25th.
I'm sorry I'm asking a million questions. But yeah, 7 days does sound like a lot but for a pregnancy test it is the difference between positive and negative. I read on clear blue website it can detect up to 4 days before period 56% of time. But according to lpm I tested 6 days before period. Which is why I asked if period would adjust itself
The new due date is October 10th by the way. Do you know what may cause early ovulation?
And one last thing then I swear I'm done in so sorry you've earned your paycheck today. But how long does it take implantation to happen. How many days dpo will it take for hcg to reach 25mu?
I'm sorry I'm asking a million questions. But yeah, 7 days does sound like a lot but for a pregnancy test it is the difference between positive and negative. I read on clear blue website it can detect up to 4 days before period 56% of time. But according to lpm I tested 6 days before period. Which is why I asked if period would adjust itself
The new due date is October 10th by the way. Do you know what may cause early ovulation?
And one last thing then I swear I'm done in so sorry you've earned your paycheck today. But how long does it take implantation to happen. How many days dpo will it take for hcg to reach 25mu?
Brief Answer:
Variations in your menstrual cycle are normal
Detailed Answer:
The menstrual cycle can be affected by many factors- stress, hormone imbalances, there are many possibilities but it happens once in a while for most women without any diagnosable cause. Early ovulation is less common than late but can happen. of someone has irregular cycles for more than 6 months we generally recommend a hormonal evaluation.
Variations in your menstrual cycle are normal
Detailed Answer:
The menstrual cycle can be affected by many factors- stress, hormone imbalances, there are many possibilities but it happens once in a while for most women without any diagnosable cause. Early ovulation is less common than late but can happen. of someone has irregular cycles for more than 6 months we generally recommend a hormonal evaluation.
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj
Thank you doctor. When does implantation take place and around how many days will you get a positive with 25mu urine test?
Brief Answer:
Implantation takes 10-12 days
Detailed Answer:
Implantation takes place somewhere around 10-12 days after conception. I am located in the U.S. so am not sure what the exact parameters are for the particular pregnancy test you use, but most of them can be positive about 3 to 4 days before your period is due. Thank you so much and have a good day.
Implantation takes 10-12 days
Detailed Answer:
Implantation takes place somewhere around 10-12 days after conception. I am located in the U.S. so am not sure what the exact parameters are for the particular pregnancy test you use, but most of them can be positive about 3 to 4 days before your period is due. Thank you so much and have a good day.
Note: Revert back with your gynae reports to get a clear medical analysis by our expert Gynecologic Oncologist. Click here.
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
