My girlfriend had her last period on Dec 12th. About 2 weeks ago, while we were having sex, she began to bleed, and so we figured she was getting her period. We stopped. Two nights later, she still didn't have her period, and we had sex again, at which point she began bleeding again. It is now two weeks after the original incident and she still doesn't have her period. Not only that, but she has stopped bleeding during sex. What does this mean? Is it possible she is pregnant? I keep thinking that if she bled at all, she cannot be pregnant (because otherwise what would be bleeding? She has no pain when it happens).
An interesting thing to consider: Before her last period (Dec 12th), similar thing happened where we had sex and she bled. However, that time she got her period within 1 week of this happening. Any advice?