Could I be pregnant if my patch was iffy?

I've had this question in the back of my mind the last two months since my boyfriend and I screwed around in the shower. We didn't have , but he came. And I'm not sure but he may have gotten some on me. I've been on birth control a while, but my patch was iffy and kept coming off. I switched to depo because I couldn't remember to change my patch, and usually your period goes all wacko and heavy and spotty. I haven't had a period in two months. Is it a possibility I could be pregnant?