trouble!!!

Okay guys Soo my boyfriend of 6 months tomorrow just told me that he has a baby on the way . He told me the story of how it all happened two weeks ago and I accepted it and everything . Now the girl that he had sex with is claiming she is pregnant because she says she eats a lot and pees a lot and has stomach cramps . I really don't kno what to do because I feel like I have been faithful to him this whole time and for him to go out one night and get drunk and for this to happen is totally crazy . Need help .!!!!!