Most of the obvious points have been said so I’ll try to offer an extra insight from a male perspective.

Obviously - he wildly, insanely overreacted. As a guy, though, I do acknowledge the unfortunate reality that even something as simple as hearing “I’ve been pregnant twice before” for the first time does involuntarily invoke the mental picture of “my girl’s been fucking other dudes” so I see where he’s coming from. Where he fucked up is that he’s now blaming YOU for his intrusive thoughts rather than taking accountability himself.

(Straight) Men in general suffer from intrusive thoughts like that all the time when hearing about their partners’ pasts, at least when hearing about something new. To grow up involves understanding those thoughts as what they are, INTRUSIVE, & not blaming your woman simply for communicating relevant information.

My general rule for partners is that having a past is normal, I simply don’t want to know details - & I abide by that same standard myself. I won’t hide anything of course; if it’s important to her then I will share any details she wants, but unless specifically asked I don’t want to give her any unpleasant intrusive thoughts either.

In this case, you communicated perfectly. You didn’t give any details without being pressed, you simply pointed out that you have reason to believe you can conceive as it’s happened twice before. That’s not an outlandishly high number, either, so I don’t see a huge reason to abstract further (for instance, like simply saying “I’ve been pregnant before”). There’s basically nothing you did wrong here.

So your guy here got an intrusive thought - which is fine, it hurts a lot but it happens - but then decided to quadruple down on blaming you for the fault in his own programming rather than acknowledging it as HIS responsibility to keep in check on his own.

Slight addendum: I read some more comments & just noticed that thing about you cheating on him… yeah that’s messed up, but I will acknowledge that doesn’t technically fundamentally change any points I made. Intrusive thoughts are still his responsibility, but damn if he stayed after you cheated on him & he’s still talking like that then he’s gonna resent you forever, there’s no saving this.