My doctor started me on birth control pills 2weeks ago due to my abnormal cycle,my cycle just came on yesterday it usually comes on the 12th, y early?

Early cycle: Your doctor is giving you BC pills to regulate your cycle. It takes a few cycles to establish a stable pattern monthly. Make sure you follow up with your doctor and take the pills as she/he prescribed.

BCP's and cycles: You are being cycled with a birth control pill. Sometimes it can take several cycles to be regulated. If you are still bleeding midcycle after three months, please call your doctor to switch to a different pill.