It all starts with “menarche,” the horrendous word for a young woman’s first period. In some cultures this is celebrated, and women get to laze around in pools of chocolate with their besties (read Anita Diamant’s The Red Tent). In others it’s seen as downright dirty when, c’mon, we all know we can get a lot dirtier than a little blood.

In my culture, which I assume I have in common with many of you, it’s largely equated with womanhood and sex.

I didn’t get my first period until 15. I know some bloody cramps are nothing to wish for, but I was jealous of all my peers who were figuring out the best way to shove cotton up their you-knows.

Actually, I was pissed that I would be assumed less sexually knowledgeable or womanly because of it. So, like my fake toilet paper breasts, I also got a fake period. But before you start pitying my poor, flat-chested, non-bleeding eighth-grade self, just think about this: at least my lagging real-life period bought me time to get my information straight.

Now fluent in The Monthly, I want to speak on behalf of my school-time peers —for the one who was walking around with a cardboard tampon applicator stuffed up her hoo-ha, only to find out that she was “doing it wrong!” in a bathroom full of teenaged mean-girls. Or for the one who’s prim and proper mother never told her what a period even was, so when one day her vagina started bleeding, she mournfully prepared herself for death-by-uterine-lining. If only they had known.

Women are born with 1 to 2 million eggs, which drop to a meager 300,000-400,000 by puberty. And that’s all we get—for life. We stash them in our ovaries and throw an average of one or two down the toilet every menstrual cycle.

A “cycle” consists of three stages and generally lasts 23 to 35 days. First, we ovulate, during which an egg takes a trip from the ovary to the uterus. This can sneak by unnoticed, but some women feel bloated, crampy or grumpy.

Then comes the “secretory phase” which is when we’re most fertile… and horny. The hormone progesterone spikes, and we become easily aroused and ready to romp! This can make for some excellent sexual chemistry, but can also make for some unexcellent accidental pregnancy. It’s a good idea to double up on birth control during this phase if you’re not eager to parent. This phase lasts about two weeks and then, if you didn’t get knocked up, you bleed!

When we bleed, we get rid of that month’s unfertilized egg and also our unused uterine lining. If our egg had been fertilized, our uterine lining would have kept it alive, but because it didn’t, we toss it. Periods are super-customized, so a light, medium or heavy blood flow for two to seven days is all considered “normal” and can change based on your diet, stress, exercise and sex patterns. Some people skip periods and some get them like clockwork. The healthy minimum is to get your period at least four times a year, but always check with your doc. Also, you can still get pregnant during your period!

Starting your first menstrual cycle means that you are officially ready for fertilization, but it doesn’t mean that you are officially ready for sex. Scarleteen.com reports that female puberty “typically begins six whole years earlier now than it did on average less than 200 years ago,” with some girls getting their periods as early as six. Why? Hormones in the meat we eat, environmental changes, pesticides, preservatives and unhealthy diets have all been suspected but never proven.

But this doesn’t mean that girls are sexually maturing faster. Even at age 15, my period didn’t dictate my sexual maturity, physically or emotionally. Being ready for sex starts in your brain, not your body. So whether you’re a frightened mother fretting over her young daughter or an impatient teen waiting for the green (well, red) light to start your sexual exploration, don’t worry—your period’s just the vagina’s way of taking out the trash.

Still wondering what to do with that cardboard tampon applicator? Check out Scarleteen.com’s On The Rag for helpful tampon tricks.