I started taking trisprintec three weeks ago and on the third week i started spitting then the next week (now) i am full on bleeding. is it normal?

Normal: Last time I checked, the oral contraceptive pills provide a roughly 4 week interval between periods. Moreover, spotting is also characteristic with new pill use. Doing the math, this appears "normal" for its' use.

Maybe: Its not uncommon to have some breakthrough bleeding when you first start taking a new birth-control pill. It usually goes back to normal after a few months. Keep taking it as prescribed. If your bleeding is heavy or you have pain in your lower abdomen, you should see your doctor. A pregnancy test is also a good idea the first few times this happens. Best wishes!