Spotting for 10 days

I am on the patch, have been for 2 years or so and ALWAYS have regular periods with cramps for 1 day or 2 and I always know when it's going to start..well a week before I started spotting a brown discharge lightly for 2 days, then had more red spotting (heavier) for a few days and now back to on off brown/red. This has been going on for 10 days now with cramps and lower back ache.

What could this be? I never have spotting before my periods, they're always regular and this is just so abnormal. I cant get to doctor yet, but i am a bit worried.