How do the hormones in birth control prevent pregnancy?
Different methods of birth control use different hormones. For example, the Nexplanon uses progestin (a synthetic version of the hormone progesterone, which is naturally found in the body) in order to thicken the mucus on your cervix, which stops sperm from swimming through to your egg. When sperm can’t meet up with an egg, pregnancy can’t happen. Progestin can also stop ovulation (when ovaries release an egg) so there’s no egg to fertilize. When eggs aren’t released, you can’t get pregnant.
Other methods, such as certain brands of the pill, contain progestin as well as a form of estrogen called estradiol. Even though they're different hormones, they are all doing the same thing--thickening the cervical mucus and stopping ovulation from happening.
Why do I have to wait 7 days after getting the NuvaRing to have sex?
The reason you should wait at least 7 days after getting any of the hormonal methods is that your body needs to adjust to the new hormones. While it's adjusting, the birth control won't be as effective. So it's best to abstain during that first week, or if you choose to have sex, use a backup method like a condom.
Why am I so moody all the time? I get in a bad mood and yell at my parents and I don't know where it comes from.
It's really common to go through mood swings when your hormones are changing, and that's exactly what happens when you go through puberty. As you mature, it's normal to experience increased irritability, intense sadness, and frequent frustration due to the chemical changes occurring inside your brain. Sometimes this can be made worse if you're taking a form of hormonal birth control, although other people report that being on birth control actually helps with their mood swings.
There are lots of things that can help with mood swings, but every person has to figure that out for themselves. Doing something physical that "gets you out of your head" or listening to music are often helpful.