think i might be pregnant

Lol x

i had sex without a condom, i was very drunk and i’m sure he pulled out but his dick was sticky (precum) i’ve been feeling really dizzy, keep needing to go toilet, having headaches and pains in my lower stomach and back, been feeling really nauseous. my period is due next week and i just went toilet and there was a light/bright red blood, i need advice i’m only 15! could i be pregnant?? what’s the chances...someone please help a girl out😩