I’m Spotting..Help!!

Okay I’m 17 and I’m experiencing some really weird stuff. So my boyfriend that I have been dating for a little over a year and I have had sex with each other twice, once 3 momths ago and the second time about a few weeks after that. We haven’t been sexually active with anyone else (we both lost our virginity to each other). Both times we had sex we had used condoms because we don’t wanything bad happening like me getting pregnant. Anyways, whenever we hang out and get a little intimate, such as me giving him a handjob and we make out, I get really really horny and wet, but I’ve noticed that I spot whenever this happens. Normally I do just a tiny bit, but tonight I had a lot of blood after he came over. The only thing different this time was he fingered me and maybe that’s why it was a little different? The point is, I’m freaking out because I have NO clue what the spotting could be from!! I had my period come the last couple months so I don’t think I’m pregnant but I’m really scared that something bad is wrong. Does anybody have any advice or any idea why this could be happening and what I should do?