Bleeding while taking yaz?

I have been on yaz for almost three months now. The first month was great, no breakthrough bleeding, and i got my period on the day i took the 2nd 'sugar pill' and my period was painless, no cramps or anything,which is great b/c before my periods were unbearable, but this period stopped when i to the 2nd horomone pill of my next pack. About a week later i started having horrible cramps, then breakthrough bleeding that lasts a couple of days, goes away for a day, then comes back. Usually its pretty light but the last couple of times it is like i am getting my period b/c it is so heavy. I haven't missed any pills, i take them within a 1 hour time frame every day. should i go talk to my doctor right away, or wait till my checkup when my prescription runs out?