What Causes Bloating Of Abdomen And Stinging Sensation While Drinking Water?

I think my friend is pregnant there stomach is getting bigger and harder when they drink water it stings like they are drinking vinegar thas what she describes it to me as she has the implant but in oct or nov time she had an antibiotic to stop the contraseption effects she also is bleeding still and I'm worried for her but she won't go docs she doesn't smoke but on Tuesday she is going out drinking and I'm scared if she is pregnant it's going to effect it what can I do?