Very light "period" spotted for a week, negative hpt?

i had unprotected sex on june 1. exactly 8 days later, i started spotting but my period wasn't due for another 4 days. it wasn't enough for a pad or tampon, started off brown then pinkish red, then a reddish brown, then a light pink color. it lasted for a week on and off. my periods are very regular with heavy bleeding. i took a couple HTP and they all come back negative. i feel really warm all the time, my head hurts sometimes when i get up to stand, i also sometimes feel nauseated. i am peeing more than usual. and my chest don't hurt but they are starting to get these bumps. idk someone please help me!