Me and my gf had unprotected sex, is it possible that my girlfriend is pregnant even if she had just her menstruation?

Is my girlfriend pregnant?

Me and my gf had unprotected sex last week Wednesday, and I pulled before I released. By Friday she said she had her menstruation, then by Sunday and Monday, she said everytime she peed, it was red, by Tuesday it was gone but then this is where her pain above her abdomen happened, along with lower back pain. Until now she is still having those pain. Is it possible that she is pregnant?