husband wanting to leave on a week cruise

I had a breakdown when my husband told me he wants to go on a week cruise with a bunch of single guys that I've never met before. He'll be on the other side of the country. He thinks I'm being dramatic. Mind you I'm 20 weeks pregnant. How would you react? He told me to come with but Caribbean is a little too much with Zika so I said no but that I didn't feel comfortable with him going either. 
I'm not worried about him cheating. It's the fact that he wants to act single all of a sudden. Like idk where this is all coming from. I think it's the fact that he's hanging around these young single dudes. He's not really talking to me either because he said I'm acting very insecure and immature 🙄 I'm over it. As long as he doesn't go lol he better not!! I think he needs an eye opener. He's got responsibilities to take care of. Ughhhh!!! 😤😤 he said I'm stressing over nothing and I'm harming our baby but he brought this on to me, not vice versa.