Scarleteen

Hello. I'm Nini and I am 16 years old. I have a boyfriend and we are still going strong for 8 months. I am taking the pill for 24 days. I have some questions about taking the pill. Sa last Friday, (August 19,2016) I was supposed to take my placebo pills but I didn't because my boyfriend and I decided to have sex on that day so I started a new pack. But today, I decided that I want to have my period and take the placebo pill. Can I do that? Can I take the placebo pill whenever I want? Can I take the placebo pill tonight? If not, what should I do to have my period this week? I really want to have my period because my period didn't come last month. And also, I'm having cramps while on the pill, is that okay/normal?

You cannot take the placebo pills whenever you want: in order for the pill to be effective, you need to take it as directed, meaning that you take all of the active pills (in order) in a pack before you take the placebos. Since you started a new pack of pills without taking the placebo week, you'll need to finish that whole pack to continue to be protected from pregnancy.

Per having a period, at this point you just have to wait until your next placebo week, although some people find that when they go straight into a new pack of pills without taking the placebos, their period shows up anyways.

Cramps are a fairly common side effect of the pill, and side effects are to be expected when you first start any medication. A general rule of thumb is to give your body three months or so to adjust, and then if you're still having side effects that you can't deal with, to talk to your doctor and see if there is a different brand of pill or even a different method of birth control all together that might be a better fit for you.

When the time comes wherein I should take the placebo pills, can i only take 3 or 4 of them?

You should take the placebo pills after you've taken all the active pills. You should be taking the pills in the order that they're laid out in the package. And yes, you should take all of them. You can read more detailed directions on taking the pill here:
Combined Oral Contraceptives (The Pill) (as well as in the directions that came with the pill)