Started a business at bad time.

So my bf decided to start his own mechanic business and I think it wasn't the time to start it. I'm 28 weeks pregnant with our first baby together (huge accident baby as we used condoms and birth control) we don't have a place together yet and he decides that this was a good time for him to spend extra money getting the paperwork and stuff for his business. I work only part time right now due to a car accident injury that I'm still dealing with so us getting a place together anytime soon is looking gloom. My bf works full time and now is working extra for his business (he doesn't have a shop just does work at people's houses and his house). He's been talking about all the stuff he needs and wants and I'm like we need a house for our kids (I have 2 from a previous relationship and he has a daughter from a previous marriage so 4 kids including our unborn son). I told him that I didn't think this was the time to start his business and he should have waited til we had a home. I'm not hating on his dreams but he really should have waited til we had a stable home. I want to put just my name on a mortgage or rental agreement because I'm afraid he'll go into debt with this business and I don't want a house to be involved. What do y'all think? Should I just not worry about it?