Lower stomach cramps,

I’m supposed to start my period in 4 days but I haven’t had my regular period symptoms I’ve only had acne breakouts but no sore boobs or thigh cramps which are normal for me. I do however have lower stomach cramps? It’s nothing painful itsalmost similar to the sore feeling of an ab work out or sit-ups.... is this a sign of my period? I had dark brown spotting for a day a week before my period...