Confused about Conception

[megan1978]

I am confused and so worrysome about my conception date. My last menstral period was Jan. 23rd. Which would mean I ovulated somewhere around the week of FEB 3rd - 10th. I had sex with my partner during that time, (2 times, the 6th and 7th) so those dates def make sense. The dr. said after my 5 week ultra sound that those were the dates when most likey conception occured. My due date is Oct. 30th. However, what is throwing me off is that the period before that was Dec 19th which means that month was not a 28 day cycle, more like a 34 day cycle. I had sex with someone else on Feb. 15th. But I also took the morning after pill within 72 hours. I found out i was pregnant March 1st and immediately had an ultra sound. I am so panicked that there is a chance that my son could be from the person I had sex with on Feb 15th. According to conception calendars,  on a 34 day cycle,  ovualtion would of occured more around the 14th of Feb. So I am just scared and confused and am not sure. Wouldnt the drs. would of said the week of the 15th rather than the week of the 3rd of feb...but if they are assuming i had a 28 day cycle  - wouldnt they be wrong or can they tell from the ultrasound measurements? Any insight would be appreciated.

[megan1978]

Thanks for the feedback

[smjmekg]

They CAN tell the gestational age of the baby by measurements done during an ultrasound, but itt can still be off by a few days. If you want to be 100% sure you'd need a DNA test, but I'd day it's your partner's baby.

[kskart]

actually, they cant tell by measuring the baby from the U/S. its just an estimated guess from what i was told. you should tell your doc about that, but you will prob need a DNA test either way, just to make sure who the father is.

[nickieb85]

They can definitely tell from the measurements. I don't think you have much to worry about but you can always have a DNA test done after your son is born.