Abnormal bleeding

So I'm on the pill and I was taking the sugar pills , I missed the last 2 ( this was almost 2 weeks ago ) and ever since than I'm still bleeding but it's only light and. NOw it's done dark and clumpy like discharge and old blood and new blood. I'm still taking the pill and I'm very sexually active with my partner. i was wondering if there is a chance I could be pregnant or it's just my body, has this ever happened to anyone? I'm 17 and have never had this happen to me before, I'm thinking if the bleeding and or spotting doesn't stop before the weekend I'll go to the doctors