Am i imagining that i have pregnancy syptoms or are they real?

I had my period last month, but I am not sure of the exact dates ,however, I do know that I started on march 14th or 15th of the previous month and it was a little late in April if I remember correctly, i think i started somewhere in the 20's (yes i know i probably should keep up with it better lol). I had May 5th without protection but midway he put a condom on. Now, 3 weeks later I have fuller , headaches, late period, broken out skin, I feel like my stomach looks a little bloated, and I have this sick feeling kind of nauseous, but maybe its because I think I am putting on a cold. anyways, these are signs of pms I know, but i never ever get them, ever.. well I took a pregnancy test yesterday and it showed up negative, but could it be too early to tell since I actually don’t know when my period is supposed to be? and just recently i started spotting, its very light pink, like barely there. so i dont know what that means. Help please! im flippin out!!