Before I start, I did not cheat on anyone. I am 4 weeks pregnant and slightly unsure of who the father is. I have a very normal period cycle, my last period was Aug. 3rd-7th and according to my period tracker my most fertile days were Aug. 13th-17th. My due date is May 10th which would mean my conception date was Aug. 17th. I had unprotected sex with my ex on Aug. 12th and Aug. 14th, both occasions he ejaculated inside of me. On Aug 17th (technically the 18th cause we had sex around 12am) I had a one night stand with a guy, it was unprotected but we used the pull out method. Personally, I'm convinced my ex is the father even if the dates of intercourse are close because of of my ovulation period and the fact that sperm can live for 3-6 days. However, I'm obviously not 100% sure and the fact that I had sex with the one night stand on the day I probably conceived, has me second guessing I would really value a non-judgmental second opinion. Thanks!
No one can tell you exactly when you conceived. It is not immediate.
You'd normally be expected to ovulate between days 11-16 of your cycle, Aug 14-19. Yes, sperm can survive up to about 5 days, the egg up to about 2 days. You didn't actually become pregnant until a few days later.
Either male can be the father.
You need a DNA test. There is no way around it.