Pretty sure my boyfriend is cheating on me

I'm not sure how to approach the situation in such a way that he isn't just going to lie about it, and I'm not that person that's gonna try to sneakily go through his phone for evidence even though it's the only thing he wouldn't be able to deny. I'm just exhausted and part of me wants to not even address the problem, and part of me wants to rip his testicles out through his nostrils..mostly I just want him to know he isn't getting away with anything and obviously I'd like for him to stop...I just don't know what to do. At first I thought I was just being hormonal and crazy and dismissed it but more and more things just aren't adding up. I don't know what to do. Spare me the "leave his ass!" because yeah, I know. That's what you're supposed to do. Bit hard when you have a house together and were planning on not working after the baby came. Just not a situation I ever expected to find myself in and I'm a little lost