I get the 30th of December guy, if he is the one closest to your ovulation/conception date. None of the earlier times was close enough to that date.
If you are doubting the ultrasound (admittedly that is a rather long time span for sperm to last, i.e., 7 or 8 days), go get another, ask them for the due date, and count back 266 days.
Regarding the missing period, women do miss their periods for other reasons, that's not enough of a clue to discredit the ultrasound (the baby measures 6 weeks not 10 weeks after all).
But because it is a bit unusual for sperm to last as long as it would have taken for you to conceive around the 7th or 8th, you would not be too careful if you got another ultrasound.
Chances are the only way you are going to find out who the dad is thru a dna test. The timing and dates are close enough that it is possible for either one to be the father, just looking and counting quickly on my calendar. I would discuss this with your doctor, and see what he/she suggests.
can i ask also is the 6 weeks and 1 day give a day or 2 the time of conception i have seen the baby and it is defiantly size of 6 wk with a good heart beat 5-7 crm. I am assuming that you would have to have concieved then for a baby to grow?? If it was 30 dec it would have been 5 weeks at scan?? Thank u.
thank you for your reply so are you thinking the one night stand on 30th dec?
combination of ovulating earlier than you think and sperm can live up to 5 days with the right conditions, could explain it. It is also possible that the dating scan is off by a few days.
I went thru Ivf, and my first ultra sound was off by 2 days, based on knowing exact date of conceptions and transfer. So these things can have a little play.