Question: Please Please Please help me.

My boyfriend and I found out that this girl he was seeing before me is pregnant and he might be the father of the child along with another guy. Her due date is November 13th 2014, this is based on a dating scan. My boyfriend used protection and last slept with her the 2nd of February 2014. She had drunken sex but claims she used protection with another guy on the 26th of February 2013.

On top of this. She had a period January 9th and also felt like she was going to come on around the 6th of February but took Norethisterone 5mg a few days before to delay her period. She then came on her normal period after stopping the pill around the 12th till the 17th of February. My boyfriend knows this because the last time he saw her was the 15th of February and they did not sleep together because she was on her period. Is this period she delayed her normal period or a false bleed? If it is a normal period, does that also delay ovulation.

I have asked various people and most say that the likelihood of my boyfriend being the father is very low based on the fact that her due date would be way before then if she conceived on or a few days after they had intercourse on the 2nd of February. If she delayed her period, this guy would be in the prime wouldnt he? The reason why I am worrying is because all of my calculations add up to her prime ovulation being the 20th of February 2014 (which none of these guys fall into the time frame), however, a midwife I work with said that her most likely dates of fertility are from the first day of her last menstrual period and the 18th of February which means it is possible my boyfriend could be the dad. I really dont understand, I am so upset and I just really don't want this to ruin things.

Hi, what about this pill she took would that cause her to have a false period? Why do the dating scans not add up to be either of them?

Ok. So if you take norerhisterone to delay your period and come on a week later, does that delay ovulation time too? How did this midwife come to the conclusion that her most fertile days were from her LMP until the 18th? How accurate are dating scans? Does this other guy come closer than my boyfriend?

Ok thanks, sorry to ask more. If the norethisterone 5mg made her come on a week later on the 12th-17th, does that move ovulation dates? If it did, this guy falls right in the middle of most fertile days. Could this bleeding for this length have been implantation bleeding?

If it was implantation bleeding, wouldn't her due date be much sooner than the 13th of November, like now? Also I still don't understand the affects norethosterone has on ovulation.

Is there a chance though that ovulation can be delayed slightly in a cycle? Based on her due date from the scans and based on when my boyfriend slept with her and used protection, there isn't a chance he is the father then?