a month late, exs baby

So I'm a month late on my period and I'm starting to feel.. Different. If I am for sure pregnant, then it would be with my ex. We dated for two and a half months and didn't have sex for the last two weeks of it. But I fell in love. And now I'm quite possibly pregnant. I'm 19 and he's 21. And he's already talking to another girl. I'm so lost. I do t know what to do. I would love to be back with him but I don't want him to only be with me Bc he feels like he has to. But because he wants to and Bc he cares about me. Any advice would be fantastic..