Darling, yes. You could have been pregnant from the eight you missed or the very dumb thing you did just this weekend. Why do you think the pills would be protecting you if you weren't taking them? Of course you could become pregnant ----
IF you don't go to a planned parenthood or a pharmacy right now and go buy Plan-B. You are still within the time frame for it to be effective, but barely!! You'll have to get it the 13th. However, you may already be pregnant from your earlier mess ups, so while you're there, buy a pregnancy test. Wait until it's been two weeks since this past monday, and test.
And then, definitely discuss another form of birth control. Pills aren't for you obviously, so you should get on the patch, the ring, depo, or the hormonal IUD. YES, you can get that even if you haven't had kids!!