I reckon most people who menstruate can remember their first period ― but not many of us recall how regular they were.
So when your own child gets their first period, it can feel a little concerning when their cycle doesn’t follow the classic 28-day plan.
According to the NHS, it’s completely normal for a child or teen’s menses to settle down into a predictable ebb and flow.
They add that even for adults, the 28-day rule is more of an average than a consistent rule ― healthy period cycles can last from 24 to 38 days.
How long does it take for periods to become normal?
Period regularity is governed by the hormones oestrogen and progesterone.
These fluctuate throughout a standard menstrual cycle and are responsible for things like PMS, bloating, and even acne.
But those hormones aren’t just affected by your cycle.
Things like childbirth, menopause, breastfeeding, and ― you guessed it ― puberty can all change your oestrogen and progesterone levels.
Of course, people are usually in puberty when they get their first period.
So it’s no wonder the NHS says “it can take up to 2 years for oestrogen and progesterone levels, and your periods, to settle.”
John Hopkins Medicine says that that means periods can happen more than once a month, or with a far longer gap between menses.
And that’s just considering puberty as a factor. Other things, like stress, weight changes, lots of exercise, not eating enough, hormonal contraception, and underlying conditions like PCOS and endometriosis can also affect how often your kid or teen gets their period.
When should I worry?
John Hopkins Medicine says: “If periods are coming too frequently, for example, more than once in a month, lasting longer than seven days, or if flow is very heavy during menses, this can lead to iron deficiency anaemia or low haemoglobin levels.”
If your child or teen is in pain, feels sick and/or vomits, or is generally unable to go to school during their period, you should also see a doctor.
You should see a GP if your child’s period hasn’t started by the time they’re 15, the NHS suggest.
They also say your child should see their doctor if their period is getting in the way of their life, or if they notice they:
- need to change your pad or tampon every 1 to 2 hours
- need to empty your menstrual cup more than recommended
- need to use 2 types of period products together, such as using a pad and a tampon at the same time
- get menstrual migraines
- notice painful, heavy or irregular periods
- feel pelvic pain
- have pain or discomfort when going to the toilet.