Possibly pregnant teen

I had unprotected sex with my boyfriend last week and didn't take any pills. We had sex on Tuesday and Wednesday and I got my period which usually last for 5 days on Thursday. I was done on Monday but I realized I was spotting today and I wondering if I could possibly be pregnant and if one week is too early for tell tale signs because I thought me having my period after the sex would mean I couldn't get pregnant 😥😞