I Remember Having My Last Period On The 28 Of

I remember having my last period on the 28 of November 2015, and I did not have my period since then, a while later I didn't get no pregnancy symptom but I did get spotting. On February I had sex and I would end up bleeding after I found out i was pregnant In March the 24 and had an ultra sound on April 05 my baby had legs that kicked and also arms a well shaped head the doctor told me I was 12.3 weeks but before that I felt moving around my belly on May I found out I was actually having twins! One of them was smaller than the other one and and both where already well formed. The doctor told me now I was going to give birth on October 17 but my original due date is on the well was on 5th of September I haven't had no sort of problem regarding that date and my babies seem to be doing well, I'm 35 weeks now I'm doctors view and I'm waiting on the 23 of September to get my blood donors ready for a c section babies currently weight well at 33 weeks they where 4 pounds and one of them was 3 pounds almost 4 just had 3 more ounces to go I'm not regular whatsoever I'm not regular at all. Maybe the doctors are right ?i need answers.