He has a baby on the way...

My ex and I have been broken up for awhile and have reconnected a few months ago and we decided that we were gonna start fresh and build our friendship/relationship so we can be together again and even stronger. While we were apart, I was doing my own thing and he was doing his own thing which we both had the right to do. Unfortunately, the girl that he was involved with when we weren’t together has recently found out that she is pregnant...and it’s his. She’s been pregnant for about 3 months now but she had no idea as she isn’t even showing yet and did not have the traditional symptoms. When he told me...I was shook and heartbroken and he told me he didn’t want to lose me again but I told him I needed time. We didn’t talk for 2 days but we went out and had lunch today to discuss it all...he tells me that this changes nothing between us bc in the end it has nothing to do with me and it’s not my issue, he says he’s not asking me to be stepmom and he doesn’t feel that this should change what we’ve been working on. I told him we can move forward, work on it but I’m soooo confused. I love him to death and I want to be with him but I have never imagined a kid being apart of the deal.....