How do birth control pills work to prevent pregnancy?

BCP. Works in three ways, 1- by inhibiting ovulation, 2-by creating a very thin lining (endometrium), making it difficult for a fertilized egg to implant in the uterus, 3-creates a hostile cervical mucus that doesn't allow the sperms to undergo capacitation and swim freely upstream. Also decreases to motility of the tubes making it difficult for sperm and egg to get together.
Hormones. Birth control pills contain hormones that suppress the cycle that leads to ovulation. They also alter the cervical mucous, making it more difficult for sperm to get through.

Related Questions

How does birth control pills (Microgestin 1/20 FE) work and how do they prevent pregnancy?

Block ovulation. Simply, birth control pills block both the formation of a dominant cyst as well as the hormonal surges that allow that to release an egg, thus blocking ovulation.

Can all birth control pills prevent pregnancy?

Yes. All birth control pills prevent pregnancy. They are an effective form of birth control as long as you take the pills each day. They can also help your periods to be lighter and less painful, and can decrease acne.

Other than prevent pregnancy, what are some reasons why it'd be good to get birth control pills?

Many. Great question! Many benefits to bcp's have evolved over the last 40 or so years that they have been around, allow me to list a few: 1. Regulate menses 2. Help to prevent ovarian cysts 3. Decrease heavy menstrual blood flow 4. Decrease cramping 5. Treatment for pcos (polycycstic ovary) 6. 5 years or more of use has been shown to decrease your risk of ovarian cancer in 1/2 there's more...

Does birth control pills serve any purpose other than preventing pregnancy?

Birth control. Yes they are very useful for helping painful or irregular periods and also can help mood control.

How effective are low dose birth control pills at preventing pregnancy

Very. If taken properly and as prescribed, they are very effective.
93% effective. At your age, even with proper use the oral contraceptives (irrespective of low-dose or not) as ~93% effective in preventing undesired pregnancy. Talk to your gynecologist for other contraceptive options, such as the iud that is much more effective in pregnancy prevention and can last up to 10 years without having to remember taking a pill daily.

Are low dose birth control pills any less effective than higher doses at preventing pregnancy?

Low dose. Low dose are just as effective as higher dose ocs. With both make sure not to miss a day, but with lower doses, you need to take it about the same time every day. They have a smaller window for administration and may be less forgiving. That being said, take it same time every day and it will be 99% effective.
Dose and birth contr. The most important thing will all birth control (also known as oral contraceptives) is that you consistently take them. Missing doses and taking medication with other medicine and foods (herbs) can affect the effectiveness of the birth control pills. Please know pregnancies can occur even if everything is taken perfectly. Birth control is about 98% effective so there is a chance of pregnancy.