I'm taking aubra. And I'm on the last week and have 3 more brown pills to go. But I still haven't had my period. Why?

Low dose pill. Aubra is a low dose (20mcg) combined oral contraceptive so it stimulates very little growth of the uterine lining. This means there is little to bleed off during your period so you can expect your periods to be very light, short, and you may skip some periods. As long as you are taking your pills at the same time every day, this shouldn't be a worry or sign of pregnancy. Hope this helps.