I am super worried. I know this may sound extremely strange, but my girlfriend and I are freshmen in high school. And we started kissing in the stairs. And then I started fingering her. However I felt like her vaginal fluid was a little more thick than usual. And so I took my hand out and it did seem did seem thicker. So I went to wash my hands and then when I came back, on the wall that was about 2 feet away from us was something that seem something like sperm. ( that wasn't mine because she didn't take my penis out or jerked me off at all.) i inferred that some other couple has been here before us and the guy ejaculated in the wall. I honestly don't think I touched it. But my girlfriend and I are still really worried. Specially because the (possible) sperm wasn't even mine, and we were doing this specially not to have the risk of pregnancy of sex. I don't know what to do... I'm feeling super frustrated. And I have to wait about 4 or 7 more day for my girlfriend's period to come