We had anal intercourse, I finished inside of her, any risk of pregnancy?

OK me and my gf had anal sex and I cum inside her (she was laying down facing me) then we relax for like 20 mnts and I went inside her again in the butt and she was facing me, is there a risk of her getting pg? She was suppost to have her PD last week but it didn't her Breast hurt and there no symptoms of pg, also she taking strong pill cuz of her sickness and that can affect to so please help here