possible STD??

I had sex with a new partner at the end of May. I had my period about 4 days after. and now, i am still spotting , having bad cramps, and super nauseous. my doctor took a blood test but the results aren’t back yet and i’m so scared. she said it could possible be an infection or and std/sti. i don’t even want to consider that. what do you guys think? i’m

worrying myself to death