Lost love with ex bf.. what do i do?

My ex boyfriend broke up with me in June. After we split I found out I was pregnant and later miscarried. My ex wasn't there for me and I went through a lot of heartache by myself. Me and ex have spent some rare times together over last few months since breakup. He now text me and said he's got new gf and wants to hang out with me more? I really do not know what to do cos I do love him..Do you think he's trying to get me to fight for him or be genuine mates? I just don't understand how he thinks we can be mates & have new gf so soon after everything! What do you think? thanks x