Your boyfriend might be in a confusion state, not knowing which side to lean or he might have decided to side with the ex who is pregnant with his child.
If you pester him with calls and messages it will only infuriate him increasing his dislike of you. Even visiting him might just make him loathe you. You might not know what he is thinking. The best you can do is to send him a text letting him know you love him and want to spend your life and his together. Let him know even in the situation he is in, you still love him. End the text with that you will give him the space he needs because he has decided to remain silent towards you.
Also, you need time to think things through. You should not contact him for some days to give both of you time to reflect on your relationship. If he decides to side with his pregnant ex, there is nothing you can do because he has made up his mind to raise the child together with his mother.
After some time of not contacting him, you will know what next to do - call or text him or continue with no contact or move on with your life.