Help!!!!

So I had sex 4-5 days before my period,without a condom...ops and I'm not on birthcontrol. I took test and I came out negative(I know it wouldn't show up until 2 weeks later but I had sex before in this month so I was checking if I was pregnant from the last times)My period came 8 days late but it was only a tiny bit not even enough to fill a lite tampon and I left it in all day! I had that for 2 days and it stopped. I took another test again and it still came up negative and it had been almost 2 weeks since having sex so idk what's happening. If this helps I'm only 14:) someone please answer.