She's some light on this please

Okay let me tell you my story please help me ok so I beleive semen could've got near my vagina there was no penetration as far as my knowledge and that was march 20th and that night I got my period and I'm sure it was my period then I got no periods in April I took pregnancy test and they were negative still no period then may 1st I had light (spotting) that was brown then it got a little heaver but not much I only needed a liner and it stopped after three days and it was a little red but mostly brown my stomach is killing me and I feel bloated but I don't know if it's period pains or pregnancy pains! I don't know it I'm pregnant! Please help ps I'm 16