Too early for pregnancy symptoms ??

i am on the pill and I had unprotected sex on January 15th for literally less than 20 seconds then he put on a condom. I’m supposed to get my period in a week but I feel different, my lower back hurts, my boobs aren’t sore but the veins in my boobs are really visible and I got cramps like a week after sex. I know its weird but I have like a metallic taste in my mouth and that started like two days ago. do you think it’s too early for symptoms