A wee bit worried.. A little TMI

Okay so I'm kinda gonna repeat myself but I'm going to give a little more information. Me and my boyfriend have had sex every weekend with the exception of this past weekend. We aren't TTC but we don't do anything to prevent it. Last Sunday I had a brownish pink discharge in place of my regular discharge. Then it was bright red just one time and since then it's been a light brown color. Yesterday morning I had one speck of blood the size of the tip on a ball point pen. Last night it looked like I had started my period, like old blood was on my pad and when I wiped to be sure there was a little pink on it. I've had terrible cramps for the past week and my boobs feel a whole cup size bigger. I'm so tired no matter how much sleep I get and I'm moody. Sorry for the TMI but my nipples feel weird like tingly and I'm bloated. My period isn't due until a couple of days but I have a feeling that it's not gonna come.