Ex broke my heart AGAIN. Sorry long post

Bit of a back story, we where together for 5 years, got 2 beautiful boys together and I'm 28 weeks pregnant. When I found out about this pregnancy he left me (accused me of cheating) as we where trying for a while and nothing was happening. Well we got together to talk last week, spent Monday-Thursday together it was amazing felt like none of the bad stuff happened he left Friday morning to "work away" well through the Joy's of social media I have since found out he has a girlfriend, been with her for 3 months and she is 4 weeks pregnant. I am totally and utter heartbroken. I had finally started to get over him until he made the move to want to speak last week, now I feel like I'm back to how I was, constantly crying wondering what I've done for this to happen to me. Sorry to go on, I just need to get it out.