long story about fiancé leaving 😭

Hopefully no one on here knows me in person cuz I'm sure if you read this you'll know exactly who I am. Gahh. I just want to talk about it to people who are non biased. It's a long story. My fiancé and I were together for 5 years. We were just a few short months away from our wedding. We had some serious problems as far as arguments about his family (they've treated me terribly, never liked me from the beginning) his money management, etc. but we always worked through them. It's been a roller coaster but we've never given up cuz we loved each other. He works in a college dorm and he's almost 30 years old. A few weeks ago I saw on Facebook he was adding a bunch of random students (girls) from his job. I felt uncomfortable with it. Call me insecure, oh well. I don't feel an almost 30 year old needs to be fb friends with 18-19 year old girls from his job. We got into a slight argument about it and he agreed to block them but from there our problems spiraled. It was like he was a totally different person over night. For a few days every other day he'd say he wanted to break up, then one day he decided he wanted to make it work because he owed it to us and didn't wanna give up. Everything was going really good for a few days even though it was still awkward and he was acting different so finally I was like what's going on? And he broke up with me for good. He swore up and down he wasn't cheating and that it had nothing to do it's any girls and that he didn't have very much explanation just that he wanted space to be single and figure himself out. It was like he was just a totally different person over night. It sort of gave me false hope that we still had a chance. We had been broken up for a day when I was able to get his text messages/fb messages and see that he was indeed basically cheating on me with one of the students from his job. A 19 year old. We broke up on Wednesday and he was already in this thing with another girl that same night telling her he wasn't sad he left and he knew it was right cuz he isn't sad and that she means more to him than I ever did and that's how he knows it's over. Blah blah. He knows I found out about them. He doesn't care, he's completely moved on. Says he loves me but hasn't been in love with me for awhile, there was no spark, etc.  So I asked him why he continued on with our wedding planning if that's how he felt and he said because we built a life together and he wanted it to work. I'm a wreck. Feel dead inside. Says he's moved on completely and I need to too, etc. tells everyone he's not sad. Here's the big fml. We had been trying for a baby almost the entire time we were together. We found out he was low sperm count so his chances of having a baby without help were low. Well here I am, just have a gut feeling, some weird ass instinct so I take some pregnancy  tests and sure as hell, they're positive. He doesn't believe me of course, why would he. And wants me to pee on one in front of him which I get but at the same time no. I'm not doing that. That's psychotic if you ask me, and if we were still together, he wouldn't be asking me to do that. I'm waiting to hear back from doctor about getting an appointment. I told his new little girlfriend and then hours later he texted me telling me they were done. I asked him if it was because of this and he said not really but not my business. He still doesn't want to be together and wants to be single. Im sure him and that girl will still mess around. I just don't even know what to do. Some people are telling me they don't believe he doesn't love me and that he got cold feet and got scared and is trying to make himself look tough/emotionless and is using that girl to occupy his time so he isn't thinking about everything. Idk if I believe that though. I think it's really done and over and he doesn't care. Idk what to do or think anymore.