There's a lot going on there. First--and this is not meant to judge you or your situation--the time to bond with him is BEFORE pregnancy. That's part of learning each other and includes meeting his family. The reason is that you have to get secure with each other before other stuff is added to the mix that could shake you up, like a baby or visiting parents. You have to anchor yourself so you know where home is. Obviously, this is a different scenario, but keep in mind that this is not an unreasonable request under typical and even some atypical circumstances. Don't take it personally.
Secondly, I am pretty private and introverted, as well, so I get not wanting other people, especially strangers, in your intimate space, especially during the vulnerable time following childbirth. Don't take this one personally, either. You're super sensitive about this because of that part of your personality and because you are pregnant (and nesting and protective instincts are high) and because they are strangers to you and because you are fighting really hard to create a bond with your boyfriend. It's beyond awkward for you and seems to be completely out of your control. I get that you guys are busy, busy, but I suggest that you find time immediately to seek counseling for tools to build your intimacy. You are behind the curve on having a healthy and stable foundation on which to build your family, and you need to get on it.
Thirdly, does he plan to host his family in your home? You can control some of that. Surely, they can understand your need and desire for privacy, especially since you have never met. They should stay offsite. That might, also, limit the time they can stay, if they're spending money on a room. Find out how soon after they plan to come. Unless they have plenty money and nothing else on the calendar, they won't likely board a plane as soon as you go into labor, so you might have a little space to breathe before having to meet them. Don't worry about being pretty or on your best behavior. Just be a mother to a brand new baby; they should get that. In fact, contact them right now, and start building your relationship with them. That way, they're not complete strangers when they get there. You can even tell them that you're talking to them so they won't be strangers anymore, since you don't want to have to deal with strangers.
Fourthly--and I think lastly--babies are expected to bring families together. Right or not, people come from far and wide to coo over new babies. You are hoping that for your immediate family, but there's more to this picture, and you have to allow your baby to be a blessing to as many lives as will happen while he/she is at your breast. This doesn't mean that you have to pass baby around the room or leave baby overnight. Just let the mere presence of the baby work its magic. The fact that they want to visit after so much time apart could be a sign that the magic has already begun. It's not automatic, though. There is work to be done behind the scenes, and it starts with you. Right now.
We mothers like to think of our babies as our possessions. We do that when there's some other aspect of our lives that we badly want to control but can't. The sooner you recognize it in yourself, the sooner you can address it, and everyone can be happy. I certainly don't know your relationship with your boyfriend, but what if your graciousness (as much as you're comfortable with) with his parents helps to ease his anxiety and endears him to you? What if his parents feel well received and become your strongest allies and their healthy relationship gives you and your boyfriend a good model? What if the only way that this could have all come together was for you to be having this baby in this moment?? When you wish and pray for something and you truly release it, you get more than you could have dreamed of. You have to release it, though. Just practice: Close your eyes and ball your fists tight. Inhale a big breath and hold both positions. Upon release, let go of that breath and open your hands.
Good luck to you, and congratulations on that sweetness in your belly!!
ETA: Not sure if you just added this or if I just missed it--(1) Your talking to him about how you feel ends up in a fight, so you just don't talk? No, ma'am, you do not get to put that all on his plate. You two created together whatever dynamic you have, and you have to take responsibility for your part. Figure out how to talk to him in a way that he will listen. Start by not attacking him or operating from a defensive position. (2) He doesn't know where he stands with you if you aren't all in. You can't straddle the fence and demand commitment from him. If you know that there is a problem and you are not willing to do everything you can to fix it, then you are not all in, and you might as well leave now. It will NOT get better as long as you hold this position. (3) He probably thinks of it as YOUR house because you have not allowed him to treat it as his house, too. You probably remind him that you have the money and the house, and demand that he prove himself worthy of sharing it equally. You treat him as a hired hand. The way that he maintains his sanity is to create boundaries in his own mind, so he can have structure. You will not get him that way. You will surely push him away, and then you WILL be on your own with a new baby. You will be bitter. You will not recognize the role that you played in the demise of the relationship, so you will carry that bitterness into how you co-parent with him. That is the example that you will set for both of your children, and you will not even understand why. It's not about just you anymore. You owe it to your child, your future child, your boyfriend, yourself...to put all your resources into making this right. Otherwise, you can't say that you really tried.