Published: October 15, 2025

Estimated reading time: 3 minutes

Bleeding during your first periods may only last a few days and be very light — sometimes as little as a few spots of red or brown blood.

If the bleeding lasts more than seven days, you should contact your pediatrician or a pediatric gynecologist.

It will take your body some time to get into a regular pattern, and settling into the typical 23- to 35-day menstrual cycle — the time from one period’s start to the start of the next — can take years.

Menarche — your first period — happens around the ages of 12 and 13 for most, but some start earlier and some start later. Your first period typically happens two or three years after your breasts and pubic hair start to grow.

Keep pads or tampons in a school bag or purse to help make sure you’re ready for when the first period begins. “Period panties” look and feel like regular underwear, but have an extra layer of highly absorbent material sewn in. Tampons or a menstrual cup might take some getting used to, so plan on using pads at first.

“Knowing what to expect as you enter puberty is the most important part of preparing for your first period,” said Virginia L Menche, M.D., pediatrician with Norton Children’s Medical Group. “Cramps and breast tenderness are common. Exercise, a heating pad or over-the-counter pain relievers like ibuprofen can ease symptoms.”

You’ll gain confidence as you become more familiar with what a menstrual cycle involves, how long a first period might last and the signs of menstruation.

Menstrual periods are natural changes and a sign that you can become pregnant if you have sex. The uterine lining, menstrual blood and tissue is shed through your vagina. At the same time, hormones stimulate the ovaries to produce follicles with an egg inside and signal the uterine lining to thicken and prepare for a possible pregnancy.

The dominant follicle releases an egg — ovulation — about 14 days after the start of bleeding. The egg starts traveling down the fallopian tube toward the uterus. If the egg is fertilized during this week or two, pregnancy begins. If not, the cycle starts over again with menstruation.

It’s common during adolescence for menstruation to happen without ovulation. Without the progesterone production triggered by ovulation, the uterine lining thickens excessively, eventually becoming unstable before it sheds. The result can be heavy bleeding and irregular periods.

A period may seem like a lot of blood, but usually amounts to a few tablespoons. It won’t come out in a gush, and you may need to change a pad, tampon or menstrual cup about three to six times a day. Period blood may leak through your clothes — a sweatshirt around your waist can cover stains until you can change your clothes. A spare pair of pants or tights at school or in your bag can come in handy.

If you need to change your pad or tampon every hour or two or if your period lasts more than seven days, contact your health care provider. If you are light-headed, dizzy or have a racing pulse, see your medical provider right away.