Maybe your child has complained of pains that sound awfully similar to cramps, or you’ve noticed they’re having more and more breakouts lately. And then boom, it happens: their first period. But then the next month comes and… nothing. Now you’re frantically researching, “Is it normal to be irregular after your first period?” You’ve had your period for decades now but somehow can’t remember how long it took yours to show up on schedule.

Well, according to gynecologists and children’s health authorities, it’s totally normal for your kid’s period to be irregular. In fact, it might go on like that for years — and that’s OK.

Is it normal to be irregular after your first period?

In the U.S., the average age of menarche — the medical term for a first period — is between 12 and 13 years old, says Dr. Tara Streich-Tilles, assistant professor of obstetrics and gynecology at Duke University School of Medicine, and most kids will have started their cycle by age 15. Surprisingly, she says it can take years before your child’s period actually starts coming on a regular monthly schedule.

It can be normal for periods to be irregular in the first couple of years after they start because of something called ovulatory dysfunction. “When an individual first starts menstruating, the brain has to learn how to talk to the ovary. That ovary has to learn how to talk to the uterus, and then the ovary has to go back and talk to the brain. And it can take two, sometimes even three, years for this communication pathway to become mature,” says Streich-Tilles. She likens it to a game of telephone, one that takes a couple years’ practice to get a clear message from one end to the other.

Instead of monthly, most kids in that first year or two of irregularity can expect their period every 21 to 45 days, Streich-Tilles says. Seattle Children’s Hospital says your tween can go up to six months between the first and second periods and up to four between their second and third periods, so don’t be alarmed if it feels like their cycle disappeared. Their flow tends to last less than seven days, and they’ll likely use six (or fewer) pads or tampons on “a heavier day” of bleeding.” The “vast majority” of people will have predictable periods within three years after their first one, she notes.

Should you talk to your child’s doctor if their period is irregular?

Any time you’re concerned about your kid’s period, Streich-Tilles encourages families to reach out to the child’s primary care doctor. If your tween’s period is falling outside that 21-to-45-days range Streich-Tilles mentioned, or it’s coming every three months or less, she says it’s definitely worth making an appointment.

“There can be other reasons that the period comes in an irregular fashion, such as abnormal thyroid function or polycystic ovary syndrome. Abnormal bleeding can also be related to coagulopathy or a bleeding disorder. Bleeding disorders overall affect a small percentage of the population, but they’re found at increasing rates in patients who present with heavy menstrual bleeding and those who have to be hospitalized for heavy menstrual bleeding,” Streich-Tilles says. “Certainly anytime a patient has questions about their period pattern or a family is concerned about the period pattern, reaching out to the primary care doctor or establishing care with a gynecologist can be an opportunity to work through whether there are any other potential concerns beyond the body just learning how to have periods.”

The American College of Obstetricians and Gynecologists (ACOG) recommends that kids start receiving gynecologic care between 13 and 15 years old, and a gynecologist may be more helpful when it comes to helping your child manage their period. If you’re concerned about subjecting your kid to a pelvic exam, don’t worry. “I always like to share with my families that most individuals do not need a pelvic exam during their first visit. Just because they come to a gynecologist does not necessarily mean that they need one,” Streich-Tilles says.

While your kid is in that limbo period and their body is figuring out its ovulation situation, it’s helpful to ask them to track their period using an app or calendar. This can give them an idea of when to expect their cycle and is incredibly helpful if you do end up needing to get a doctor’s advice. (There are some excellent period-tracking apps created by women.) Otherwise, just make sure they always keep extra period products in their backpack and know they can ask you anything on their mind.