This is a great question, so glad you asked! There are many different reasons why people use the “birth control” pill (BCP.) Some may use the pill to prevent pregnancy, while others use it for menstrual period regulation (making sure your periods comes at the same time each month), period suppression (stopping your period), hormone replacement, endometriosis, or cramps.
There are two different ways you can be prescribed birth control pills: the first is cyclic and the second is continuous. For cyclic birth control pills, you take all the pills in a traditional 28-day pill packet and 21 days of the pills contain active hormones and the last 7 days are placebo or sugar pills that don’t contain hormones. There are other variations of pill packets that include 23, 24, 26, or even 28 active hormone pills. During the placebos (sugar pills), the lack of hormones will result in a period.
The second way of taking birth control pills is continuous. During continuous use, you would skip the last 7 placebo or sugar pills and continue on to a new packet. You would be prescribed a larger number of packets of pills to carry you through Continuous birth control pills work best if the pills are monophasic (meaning all one dose, all one color). In some cases, girls do experience irregular periods and spotting with continuous use. It’s important to discuss continuous birth control pills with your health care provider before you begin to taking the pill continuously, to make sure you have the right prescription. It’s also important that you check with your health insurance company to see if you can receive continuous birth control, sometimes there needs to be medical reason for this type of use.
The pill is 99% effective against pregnancy when used perfectly (i.e. taken at the exact same time every single day) and only 91-93% effective against pregnancy with typical use. It’s important to remember that the pill does not protect you against sexually transmitted infections (STIs) so it’s important to also use a condom. If you think you may be pregnant, you need to schedule an appointment with your health care provider (HCP) right away.