How To Confirm Date Of Conception Using Last Menstrual Period Date?

Posted on Tue, 10 Mar 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Tue, 10 Mar 2015 Answered on

Mon, 30 Mar 2015 Last reviewed on

Question : i went to the hospital for the flu and when they drew my blood my hcg levels were 3818 and i was informed i was pregnant. They gave me no other information. according to my last period i could be 8-10 weeks, but that just seems too far along to me. just needing some advice so that i know whether i am fat enough along to call be seen by my obgyn or not . thank you.

Answered by Dr. Aarti Abraham (15 minutes later)

Brief Answer:
Need few more details please.

Detailed Answer:
Hello
Thanks for writing to us with your health concern.
Can you tell me the date of your last menstrual period ?
Also, did you have regular cycles or not ?
Date when the B HCG levels were drawn please ?
I need these details so that I can guide you further.
Looking forward to hearing from you.
Take care.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Aarti Abraham (2 minutes later)

The blood was drawn yesterday March 9 2015
My last menstrual period was January 12 2015 and yes I did have regular cycles.

Answered by Dr. Aarti Abraham (3 minutes later)

Brief Answer:
Please get a dating scan done.

Detailed Answer:
Based on the LMP, you would be 8 weeks gone.
The B HCG levels are low , compared to 8 weeks of pregnancy .
At 8 weeks, the best indicator for dating a pregnancy is a transvaginal ultrasound scan.
Yes, you should see your OB - GYN, and have a dating scan done at the earliest.
You can reach me directly anytime using the following link -
http://doctor.healthcaremagic.com/doctors/dr-aarti-abraham/64623

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar