OK, first of all, the morning-after pill's website says it is effective 7 times out of 8. In other words, it could be ineffective.
What you're giving me is -- and please check my work with your doctor, since he is the one with your ultrasound file:
No sex with ex-fiance for many weeks before sleeping with guy B.
From conception calculator: Ovulation September 12
(remember, egg only is viable 24-36 hours after ovulation)
Slept with guy B on September 13; no condom, ejaculated in you
Slept with ex-fiance on September 15; used condom
Ultrasound October 16; 6w6d gestational age
From 6w6d GA plugged into conception calculator: Due date June 5
It sounds like quite a strong chance the guy B is the dad. Not quite enough to rule out your ex-fiance, since the dates are only two days apart. However, usually 6th-week and early 7th-week ultrasounds are spot-on for dating conception, and your ex used a condom, and you two used condoms all throughout the time of your relationship and never had a failure (meaning his method seems to be as effective as it can, with a condom). I'd prepare for guy B to be the dad, and do the DNA test with guy B when the baby comes for sure.
There's honestly no way to know right now. If you had intercourse with 2 different men 2 days apart, you're more than likely going to have to get a paternity test. Sperm can live for up to 5 days in a woman's cervix, so it's possible the Plan B pill didn't work. There are also plenty of stories about condom babies (my brother is one of them). You're going to need to talk to both of them about the situation and let them know that either one of them could be the father.
Was there no other sex with your ex-fiance except that one time that was two days after the other? Did the doctor who did the ultrasound that gave you the 6 weeks 3 days figure also give you an estimated due date? If so, what was it?
Hi yes my ex fiancée and I were not intimate at all for at least 6-8 weeks before I went with the other guy. My due date is 8 June 2014. Thank you :)
And that due date was given to you from the ultrasound at 6 weeks 3 days?
6 days 6 weeks as at 16 October. I was with the other guy on 13 Sept. My due date is approx 8 June 2014. Thanks AnnieBrooke :)