3 periods in a month?

So I got my period and it lasted about a week then two weeks later I had another one for three days then I'm getting it again a week after I had my last one! I take the pill but I think my three day period came because I skipped the pill for three days and now I'm on my sugar pills so the next one is coming I'm just really confused because the two most recent ones aren't heavy and I don't know if I should call it spotting or what. Somebody help me understand lol