Just dnt know

Me and my 2nd child's father have had a off and on relationship for 11 years we never put a title on us whn we found out I was prego we it was tough we now are at a ok place and I'm 5 months we wants us to be together but I'm not sure honestly if I can let go of the past and give him a fare chance he was I dnt want to just co parent but I dnt like not having a piece of mind in my relationships which I'm not sure he can give me