Am I being hormonal or do I have a right to be upset?

So, I am 27 weeks pregnant with my son. My fiance and I have been together for 2 years, living together our whole relationship basically. We rent a 3 bedroom duplex together and share finances. Well, a few months ago our car broke down and we just couldn't afford to keep getting it fixed so my in laws lent us their extra vehicle which we have been driving since. We finally sold our old car and managed to get $2500 for it, and after filing our taxes we found out we will also be getting $2500 back in a tax return. I was super excited about this, we have $5k sitting on a credit card that we need to at least pay off some of, and we have a new baby that will be here in just 13 weeks. Well, today while I am home sick with a cold my fiance texts me and tells me that he's going to be late coming home because he needs to go and put insurance on our new car. I was super confused so I called him. Well, apparently his parents found a car off Facebook and my fiance agreed to buy it, he's spending all of the money we are getting from the old car and from our taxes on this car and he didn't even talk to me about it. Until and hour ago I didn't even know his parents had been looking at a vehicle and now all of a sudden we are buying it? The only thing I know is that its a Chevy envoy. Thats literally it. I didn't even get to see the car first. Am I wrong to be upset about this? I dont really know anything about vehicles but I still feel like me and my fiance should have had a conversation about this seeing as how I will be the one driving it most of the time as he walks to work and I work on the other end of the city, plus I am the one who drives his daughter to school and to dance classes during our weeks with her (50/50 custody) and I'm the one who does all the grocery runs and so on. Shouldn't I have at least gotten to have some say in this car? I'm sitting here waiting for him to bring it home and I'm trying not to be upset but its really hard. What do you think? Am I overreacting? Cause I honestly don't know.