Past behavior i didn't know

Hey guys. Im having problems with my wife in terms of sexual activities. The problem started when we had sex and her v#gina was too tight and the explanation she gave me was that it was because of the long time without having sex, since im a student at University in another city far away from home. I can spend about a month tops without having sex with her, until i get home where she will be. But it is surprising me that this time the v#gina was too tight as compared to other times i was away from home, that's before we were married. We are newly married young couple by the way, only a few months in. And to add to that she is in her third trimester of pregnancy so that you may know. So my worry is that has she been cheating on me before we were married since we would have sex without having v#gina tightness problems (which means that she didn't take long without having sex, whilst i was away, with someone else). Am i being paranoid or she might having been cheating on me. And yes she has admitted to cheating on me before but during the first non serious months of our relationship when we first met. So please help me out with good advice if im the problem or she has a problem.

my wife has had multiple ex sexual partners more than me whom she cheated on as well (some).... but thats in the past

Well....you chose to marry a cheater so you are going to be paranoid......

As for her being tight....could be as simple as she just wasn't that aroused and ready for you. Occam's Razor - usually the simplest explanation is the most accurate one.

Occam's razor? what do you mean by that.

Yes you are being totally paranoid. Also, tightness has absolutely nothing to do with cheating. Have no idea where you get that from to think it's connected in any way. That's just weird and makes no sense at all.

but is it correct to assume that if someone has cheated once they will do it again. Once a cheater always a cheater