what is it!?

I'm having VERY mild sensations in my uterus. I'm not sure it's even worth thinking about, but I just wanted to ask anyway. I've never felt (or noticed, I guess) any sort of pain/sensation before my period before. What I usually get are SEVERE cramps about a day before hand and for the 1st 2 days of my period. My period isn't due until the 28th so that's why I'm asking.