risk taking behaviour and pregnancy

So I'm going through a bit of a rough patch right now and although 1 year clean from self harm I'm starting to go back to risk taking behaviour. As much as I don't really care what happens to me (I'm seeking help for myself) I know I can't handle a pregnancy. What are the chances of me getting pregnant if he uses a condom and I'm on the pill? I don't take it at the same time everyday, a few hours apart some days although I try to keep it regular. I know none of you are therapists or doctors but just needing some help. Thanks