Bleeding during active pills

So I've been on the pill for around 8-9 months now. After three months my doctor put me on a different pill because the first one wasn't affective for treating cramps. However I'm in the middle of my second week of pills and I keep getting my period. It starts as spotting and then gets a little heavier. And then when I'm on my placebo pills I also spot. Has happened to anyone else and what do you do about it?