Should I feel bad? or apologize?

So today I told my boyfriend to stop messaging girls out of the blue. Just to be saying it and he said wait who you talking about? Come here. Acting suspicious you know? So I said nothing just stop messaging them. I was heading out the door because I had to be somewhere. And then he says let me get my phone. So when I get back he gets soooo mad. Having a attitude the whole nine! And when we start talking he said how you figure I'm messaging other girls. I said because I had a message in my phone saying you was. Then he says he's mad because I'm accusing him of something he hasn't even done. Okay if you haven't done anything why you acting so fucking pissed? I've been through so much with this boy it doesn't make any sense. Him cheating with multiple girls/hookers he bought online. Having a STD while I'm pregnant. And messaging girls in the beginning of our relationship. So now he saying he's so mad because "i fucked up" for accusing him. Like okay chill. So he's acting like he's not going to "forgive" me because of this but after all the shit I've done dealt with him. Should I even let it bother me? I'm 5 months pregnant and we've been dating a year. Even if I do apologize he's not going to care