Need advice on my pregnant ex?

Ok I'm 26 and my ex is 25 we knew each other going on 9 years now and were best friends before we dated. Well she is 7 months pregnant now and we been broke up for 4 months today. We never had problems before she got pregnant but all that changed once she got pregnant and it lead to what she now calls a rash decision to break up with me. Things have not been good between us we always assume the worst and it leads to fights. In the beginning I got scared and freaked out and turned all my focus to the baby to show to her I loved our son. She said I quit caring for her and once I knew this it was to late and we weren't together anymore. I tried to get her back and be there more and she even said she reconsidered us and wanted a family with us but she never gave it a chance for us to be around each other besides the doctor appointments to see how things would go between us. She started hanging with other Guys that she said were her friends and this last one she talks to more the. Anyone else and admitted to me she kissed him and doesn't know if she likes him or not and says she still has some feelings for me. She said I pushed her to it because I quit caring again but she told me she wanted space so I backed off completely to let her come to me. She recently said she feels like she is in this alone and doesn't know if me and her are done forever. I told her she has to finally give it a chance for me to be around to prove to her I do care and can be supportive. My question is how can I be more supportive of her if she does give me a chance to be around more. I know me and her are most likely over for good because she has someone else but I still want her to know I care for her as she is still the mother of my child. What is your guys advice on this whole thing and how should I go about things.