Need advice.. 26 weeks pregnant

So my fiancé and I got into an argument.. Well I wouldn't even say argument. It was more of him telling me to leave. It all started with me bringing our 2 yr old up to his work (I needed a break and for her to nap some) she woke up from her nap and he was working on his race car (not work related).. She throws a fit and wouldn't let me put her down. I'm 26 weeks pregnant with our second child. It's hard to hold a 2 year old sometimes. I get frustrated and say "I can't handle this by myself all the time" he grabs her and tells me to get out of his shop. (He has a friend there too) I don't leave because I needed to know how he was going to get her home. He only had his race car there with racing seats and a friend with him. No kind of car seat. So that was my main concern. He keeps telling me to leave that he would figure it out. I wait outside for awhile.  They all come outside so I try to get our daughter to get in the car.. He tells her to tell me no, that I didn't want her earlier. They start walking down the road. I'm following trying to get him to put her in the car... His friend is behind just laughing at everything. Doesn't make the situation better. I finally just leave him the seat in hopes he will have a safe ride. I didn't know what else to do because I was hyperventilating and having lots of Braxton hicks contractions.. I go home and wait. He had someone drop them off at his truck. He locks the doors so I can't see our daughter. Cracks the windows to tell me to get away. Finally he rolled the window down enough for me to talk to her and to see where they were going. Now I have no idea if he's bringing her home tonight.. I'm trying to relax but it's so hard for me to breathe.. I'm so upset. I don't know why he is being like that.. We haven't had an argument like this in forever... What should I do??