Need advice!! Sorry long post

[Broken00]

So in need advice I'm completely broken and at a loss of what is right or wrong. I've been seeing this guy for over a year now he has become a huge part in mine and my two children's life's, we were going through a rough patch and took a short break he slept with some other girls during that time. We decided that we want to be together and he would be moving back at the end of the month in it's been going pretty well , until yesterday one of the girls called him and said she is pregnant she does not know if she is keeping it yet especially if he is not going to be with her, him and I talked well he cryd and told me if she is keeping it he will have to do what is right and leave me for her ... she does not know him and I are back together and he won't tell her that because he thinks it will push her too a abort the baby. My question tho is that right ?? I think he should tell her we are together she deserves to know that I deserve that. I feel so pushed to the side like I'm screaming for him to pick the family we already have over this new girl who kinda already wants to have a abortion. The whole situation makes me so sick I can't sleep he is barely speaking to me I feel so selfish right now that I want him to be with me and my kids and not leave us for a girl he only knew for two weeks. Am I selfish ?? My whole world right now is in the hands of a women who gets to decide if my family breaks up or not how is that fair?? I'm hurt beyond broken.