BC question

Okay so on the 22 my bf and I had sex using the withdrawal method and it was successful. The only thing is that I haven't been great on taking my pill and have been skipping a day and then taking two pills the next day. I'm on viorele. Now I'm taking them everyday.  I've been getting breast pain but I'm not sure if it's pms I'm on week 3 day 3 of my pills. I'm afraid I could be preg. What do you ladies think?