I Haven’t Taken Anything. But Last Month I Had Unprotected

i haven’t taken anything. but last month i had unprotected sex right after my period.. then i had another period in that same month, not long after that i started feeling nauseous everyday non stop. i took a few pregnancy tests in the beginning of june and they were negative. the nausea never stopped. now i’ve been sleeping a little more than usual and my left breast feels tender. also, no matter how much i eat i always feel hungry. but no pregnancy tests were positive