Confused

My period is always regular. Normally starts the same day each month. I normally don’t have PMS of any kind and I don’t ever have spotting. The past week I’ve been on and off spotting (only when I wipe). Until today, I’m having pretty bad cramps and I’m wearing a tampon in anticipation for my period. The tampon is soaking up old blood and some light pink blood but not enough to call a period. I thought maybe I could be pregnant as i feel off and that my body has been extremely weird lately. I took a test yesterday afternoon and it was negative. I’m unsure what’s going on. Anyone have any insight or advice?