Trust issues... sorry if it's a little long

Carman
Usually I don't ask these questions but it's gotten a bit out of hand... my fiancee and I have been together for a long while now and he still doesn't fully trust me. I'm 30 weeks with our first child. He is still deeply jaded from his past relationships and he has done better from what he has told me but he doesn't believe me about anything. I haven't given him reason to not. I just need advice on what to do. This is what happened this morning : we went to our Dr appt and he saw that I talked to a lot of friends (all female) on messenger and started freaking out because I talk to everybody when he's away. He was at work. I was at home, alone and bored. He works overnight. What's the big deal if I talk to my friends when he's gone? His defense.. I don't get on my phone when he's around. Well duh, I want to spend time with him. He works all the time. Anyways, any advice? Anyone had experience with this.