Period while wearing patch?

I am on the Xulane BC patch and starting about ten days ago, I had brownish/Black discharge and sometimes I’d wipe and there’s blood. My period just ended two weeks ago and I’ve had the patch on and changed it normally. I’ve heard of break through bleeding, but I’ve been on this birth control for about 3-4 months now and it hasn’t happened til now. I’m wondering if anyone else has experienced this. I’m getting cramps too.