Hi guys, so i am 17 and i am going to be put on the pill soon but i can't ask my mom for help because she thinks that i am going on it for irregular periods (which i am, but my doctor and i both know it's also for preventing pregnancy)

I have a few questions...

1. So when i get the pill, when can i start it? Do i have to wait until the beginning of a month or just whenever?

2. Can i get pregnant while taking the placebo pills?

3. When taking the placebo pills, is that when my period is supposed to be happening?

4. How long after taking them are they supposed to prevent pregnancy?