Who’s the dad?

So I slept with 3 guys. I know I’m such a whore🤷🏻‍♀️ but anyways I’m having a hard time calculating which one is most likely the Father, obviously only DNA tests can tell, however I’d like to know who’s more likely so I can get one from him first. I had my period November 19th-24. I slept with Guy #1 from September all the way to November 21st. I slept with Guy #2 whom I already have two kids with November 24th I was bleeding up until 2 hours before I had sex with him. I slept with guy #3 November 25th-December 4th. Based by my ovulation baby would be Guy #3 I supposedly was suppose to ovulate November 30th-December 6th, but here’s the problem I went for my ultrasound and was supposed 9 weeks and like 4 days but I was 10 weeks 6 days. Putting my due date to August 17th 2019 I’m now 16 weeks and 4 days. I did a reverse search on google it said I conceived while on my period? Thinking back I don’t remember the period itself, but is it possible to get pregnant on your period? I’ll add in that all the sex was unprotected and they came in me anytime I had sex with them, they are the only 3 men I’ve been sexual with in my life.