Confession from my boyfriend

So ive been with my boyfriend for 5 years..we have a son and another one on the way we are living together practicaly living like a married couple.. We had been fighting alot during the summer and separated for a couple of months we were still together just living seperately we thought it would maybe help our relationship and i feel like it really did now that he is back home we have the best relationship ever now but lastnight he confessed something to me.. He told me that all this years we've been together he had never forgotten about his ex.. I asked him if he loves her still because i knew he did..she was someone very important in his life before me.. Well he said he didnt that now he feels like he loves me more that he ever loved her that she was the past and now all he cared was me but that shes just always popping up in his mind and he always remembers fact he told me that while hes been with me he had tried to message her on facebook and she did answered that they talked for a couple of times and she told him she missed him but wouldnt be with him because he had a child and had a partner.. He said he kinda told her he missed her but he just wanted to talk to her ...The thing is idk what to think i dont know if i should just leave it like that or worry about it it made me feel lik he really misses her and still loves her