Horrible situation:'(

So here's what he did:(((((

The night of the races, around the time we started talking again and the time things starting looking like something serious was coming out of this, after I spent about 4 hours cheering him and his horse on even tho I didn't even wanna be there because me and my pony couldn't race til August and I didn't like being there without my pon, anyhow, after the races my friend and I even stuck around for awhile and talked to him and his parents and friends, and unfortunately his ex, who wouldn't leave his side the whole night, and cried when I took a picture with him!?¿ anyway I texted him the next morning since I was still in town for 3 more days I offered to go hang with him, so we met at KFC cause I love chicken hahah anyway later that night after a great day with him and friends we went to fireworks at the waterfront and it was good, until his ex showed up and wouldn't leave yet again. And at one point that night his friend says "Keli you know he's cranky because you're here right?" She's like "yeah" and she wouldn't leave like I was getting sour and ready to fight her. And then he told her to go home and she was like "well aren't you coming over again tonight?" And that's when I caught him in lie, he told me he went home last night. Which he should've. They got drunk, well he did for sure, she was more sober and he told me she took advantage of him, and now guess what I find out 3 weeks after that night, after all the great times I shared with him, after everything I had already done for him:( she's pregnant and I'm almost positive she did it on purpose since he was drunk and she knew he wanted me and not her. He still tells me he wants me, he still asks to hang out all the time and I don't lie about being, I just make sure I am because I was hurt so bad, the worst part was the fact he texted me outta no where while I was driving and said "kelis actually pregnant" cause she kept saying she was and we didn't believe her. What do I do? Do I move on? Do I let them be together with a baby? I cried for days, my sweet heart guy bestfriends are more friendly about this especially my bryden❤️ he's very protective and my Trey(: he says we can go over to where they live and cruise around happily to make him feel bad for hurting me and my cousin, he's annoying but very freaking caring, he drove me over there to where they live last night cause I knew the guy wasn't home and I could say I was there and couldn't see him. Someone please tell me what I should do....:/