Hi! I just started taking Aviane birth control pills. I'm on my 19th day, and two days ago I got my period. It's not breakthrough bleeding, it's a full out period. I have not missed any pills, and have been at most 2 hours late taking them. Additionally, I am not on any antibiotics. Is this normal? Will my period continue through the week of placebo pills as well? I am 17, 5'9" and weigh 160 lbs, so my doctor put me on low dose birth control, but is the dose maybe too low for me? And most importantly, when I finish this pack of pills, will I be 99.9% protected against pregnancy

Some women will have irregular bleeding when they first start birth control pills. For some, this will continue, but for most it will sort itself out and periods will become regular over time.

Whether you have additional bleeding once on the placebo pills remains to be seen. Continue taking them as directed by your doctor and do try to take them the same time each day. Some people find that it helps to set the alarm on their cell phone as a reminder.

If taking them as directed, you should be very well protected against pregnancy after you finish this pack. Do keep in mind, however, that there will always be a slight chance of pregnancy with any form of birth control.

Why aren't you asking your doctor? And, more importantly, at 17 why are you concerned about protection against pregnancy? No one should be engaging in sexual intercourse, unless they are physically, emotionally and financially ready to have a child.

No form of birth control is 100%. While the pill is very effective it has to be taken properly. Its effectiveness can drop significantly if it isn't.