Spoting after period while on yasmin birth control?

I take Yasmin brith control and have taken it for years with the exception of being pregnant. I had my kiddo in 2006 and have been on this birth control regularly ever since, I dont miss pills either and have normal menstral cycles. My last two periods have been normal but after I have had some brown spotting. The first time it happened i figured it was due to having . I am starting the second row of the normal pills tonight (i take them at night) and I noticed today there is some brown discharge of sorts and i feel lsightly crampy. I really dont know what to make of it because doing a search of the birth control it says spotting is normal at first .