An adult woman’s menstrual cycle can range in length from 24 to 38 days and in teenage girls it can last even longer. Based on how long your cycle normally lasts, if you think you’re having a second period in that stretch of time, it is important to determine if it is just spotting or menstrual bleeding.
In most cases, having two periods in a month occasionally is not serious. However, if you’re frequently having two periods in one month, you may have an underlying health condition.
What causes menstruation twice a month?
Two periods in one month can be caused by having a shorter menstrual cycle or by an underlying health condition that causes vaginal bleeding.
Reasons your menstrual cycle may suddenly become shorter include stress, illness, extreme weight loss or gain, reacting to hormonal birth control and a failure in the egg releasing from your ovary (anovulation).
In young girls, puberty can cause shorter menstrual cycles, while in older women, this can occur due to menopause.
Health conditions that cause more frequent periods
Health conditions that can cause sudden, shorter menstrual cycles include:
- Fibroids
- Hyperthyroidism or hypothyroidism
- Miscarriage — if you are pregnant, a miscarriage can cause heavy bleeding; contact your doctor or midwife urgently if this occurs
- Pregnancy — early pregnancy can cause spotting, however, you should still tell your doctor or midwife
- Sexually transmitted infections (STIs) — STIs can cause vaginal bleeding and discharge
- Uterine cysts
Risk factors for frequent menstruation
You are more at risk of having two periods in one month, if you have a family history of uterine cysts, fibroids or early onset menopause.
When to see a doctor for frequent menstruation
You should see your GP if you are menstruating more often and have:
- Dark clots in your menstrual blood
- Heavy periods
- Lower abdominal pain that doesn’t get better after a few days
- More menstrual cramps than usual
- Pain during sex
- Spotting or bleeding in between your periods — you may mistake this for two periods in one month
Treatment for frequent menstruation
The treatment for frequent menstruation depends on the underlying cause. If you have just started having periods or you normally have shorter menstrual cycles, you won’t need any treatment. However, if your doctor is concerned that the frequency of blood loss due to your periods is causing anaemia, they may suggest taking iron supplements.
In some cases, hormonal birth control may be recommended to treat frequent menstruation.
Frequent menstruation FAQs
Can two periods in a month mean pregnancy?
If you are having periods, then you are not pregnant. However, vaginal spotting, which can occur during early pregnancy, can sometimes be mistaken for a period. If you are pregnant and having any vaginal bleeding, you should tell your doctor or midwife.
Is it normal to get your period again after a week?
Hormonal changes can cause you to stop and then restart your period occasionally. However, if this frequently occurs, you should see your GP as you may have an underlying health condition.
Is it normal to have a period every two weeks during perimenopause?
You can develop shorter periods, where you may have two periods in one month, when menopause starts. However, if you aren’t sure if you are menopausal and are frequently experiencing bleeding in between your periods, which may be mistaken for two periods in one month, you should see your GP.
When do you ovulate if you have two periods a month?
If your cycle is 28 days, you will ovulate around day 14. If your cycle is shorter, then the ovulation is brought forward accordingly eg if you have a 20-day menstrual cycle, you will ovulate around day six.
