I will be 31 weeks pregnant tomorrow. My last period was the 15th of September 2008. I have been with my ex partner jim for 5 years. I was never on any thing to stop me getting pregnant, and we had sex every day. He has kids from a perivous relationship but was a big drinker and in to drugs for years. I slept with him in September 2008 till the start of October but I had a one night stand on the 26th of September. Could jim be the father even though we were trying for years and wouldn't the drink and drugs have a effect on his sperm. Could you please help me deterim when I conceived. It would be a big help if I knew around what date I conceived.

It really could go either way... the 26th puts you right around the time women generally tend to ovulate. You might follow that average, you might not, but unless you know when you normally ovulate it would be difficult to tell.

Yes, the drugs and drink may have played a role, and even though you didn't get pregnant in the previous years it doesn't mean it couldn't have happened. If you were having regular sex with your ex during this time as well, it will simply come down to having some testing done after baby is born.

According to the gestation wheel that I have at work (the one the doctors use), if your LMP began on September 15, you most likely conceived on September 30. Now, if you had sex on September 26, sperm can live in a woman's body for up to 5 days, meaning that the person who you had sex with on the 26th would be the most likely candidate to be the father. HOWEVER, this is only a guesstimate. Only a DNA test will prove it either way.

I also have you a little over 32 weeks, with your due date being June 20.