brown/red discharge 2 days before AF

Kam
So I started out with light pink spotting this morning and throughout the day I've changed a tampon 3 times (just cuz I was curious/nervous to what I'd find) and every time the tampon had brown discharge on it with a minor amount of red blood. Normally when AF comes, it's BAM she's here and in full force....parting of the Red Sea. Why am I getting so much brown discharge? Why is it 2 days early? Do I take a test to be safe? Anyone else have this? My back hurts, minor cramps and my boobs have been sore.