What is going on?

I'm not due for my period for over a week and a half, but I've been having spotting for two days now. It started with slight back cramps and peeing a lot, then nausea but not a lot. I was so sure it was AF coming two weeks early (? when I'm a super regular person) I was in shock today pulling out a tampon I'd had in for hours and it was dry. I'm so confused