Could I be pregnant??

So I have done my research and its highly unlikely that I'm pregnant, but I'm still scared. I gave my boyfriend a handjob the other day and he did orgasm... We never had sex or anything so there was no way there could have been sperm in my vagina. But, maybe 10-15 minutes later I went to use the bathroom. I didn't wash my hands before I went, which I realize now that I should have. I really don't want to be pregnant. And just so you know, I used the hand that never touched him. But I'm still worried...