Ignore Okayu (that was a very insensitive post).
First of all, congratulations! Raising a child is one of the best things I have ever done, it is a lot of work... but worth every minute.
Pregnancy is a stressful time in any relationship. When we have kids, we are doing something really life-changing for both parents. There are always strong emotions around this time. It is a little difficult that you haven't been dating your boyfriend very long. And, he is almost certainly going through a range of emotions about the pregnancy too.
First of all, take care of yourself. My advice is that you build and trust other people in your life (in addition to your boyfriend). It is very helpful to have friends and family who will be there for you and who aren't emotionally involved. Recognize that there is stress here... and use the support system you have.
Second, your relationship with your boyfriend is changing. A few months ago you were two people exploring a new relationship that wasn't permanent yet. Now you are embarking on being parents, something that will keep you working together for at least 18 years. This is a big deal, and something that you and your boyfriend will have to work through. Understand that your boyfriend is also under stress... there is no way around this.
My best advice is to keep trying to talk through it. Be honest with your boyfriend. Be kind. Hopefully he will respond the same. You might need to give him some space if he is shutting down. But, tell him exactly what you are feeling. When he talks, listen to him.
I do think that your boyfriend need to figure out what he wants... and he owes it to you to tell you what he is feeling and what commitment he has to you and to the baby. If he can't do this, that doesn't bode well for the relationship. On the other side, he may need a little time to work through this for himself (I realize that this may be difficult for you).
This is an emotional situation. there is no way around that. You have to work through it. If you want the relationship to continue... and especially if you choose to keep the baby, you need to figure out how to talk through these sometimes difficult emotions.
If you need to, couples therapy may be a very good idea. It will get another intelligent voice that isn't emotionally involved.