Need some advice.. kind words please

I’m currently 31 weeks. My boyfriend and I have been together 2 years (maybe a little less ) and we’re pregnant. However the last week I find myself distant. Like I almost want nothing to do with him. I don’t want to make any irrational decisions but I just feel like I wanna move on alone. I caught him talking to a girl back in June and we been trying to work it out but I resent the hell out of him now and it honestly doesn’t feel worth it... advice?