What Are The Chances Of Pregnancy After Having Non-penetrative Sex?

Last night I kinda made the biggest mistake of my life. Not only did I give my heart and soul to a guy who didn't even have feelings for me, but I also did it partially unprotected. I mean he didn't wear a condom in the first few minutes, and I think I should mention I was a virgin when it happened. But before that became history he did put one on, so he neither came inside me nor did he break the hymen without it on. What are the chances this could get any worse? Should I buy a second day pill?