Should brown sthinging instead of withdrawal bleeding bother me?

Do I have any reason to be concerned? I take the fourth green vines tablet today, but as long as I've always had normal bleeding so now I only have brown spots. I would add that my last ratio (intermittent) was 3 weeks ago, and last week there were nausea and diarrhea (I took extra pills when it took place up to 4 hours). I took all the active tablets at a fixed time and not one was missed. Is this a bad thing? This is my 4 blister