Irregular periods: is this normal?

How does my body know when to have a period?

Your period, or in medical terms, “menstruation,” involves a complex system. Parts of your body involved in making you have a period are in your brain and in your pelvis. Your brain sends signals to your uterus and ovaries and vice versa through messages called hormones. After specific hormone changes take place, your brain tells your ovaries and uterus to have a period. As you might expect, it takes quite a while for the body to become really good at this. Because your body has to learn how to make your period happen, your periods can be irregular for a while, up to 2 years.

What is a normal period?

What do you think a normal period is? Most people would answer something like, “it happens at the same time each month,” or “it lasts the same amount of time each month.” In adult women who have had their period for years, that is what is “normal.” In adolescents and teenagers, that usually isn’t what happens. Periods can actually skip months at a time.

A menstrual cycle starts the first day your period starts and ends at the first day of your next period. So if the first day of your period is on 11/1/2014, you bleed for 5 days and then don’t have another period until 12/4/2014, your cycle was 34 days.

Here’s a helpful illustration:

Example of Menstrual Cycle

Example of Menstrual Cycle

How long does a period last? How much time is in between periods?

Teenagers can expect their period to last anywhere between 2-7 days. Spotting between periods is common at this age and is absolutely normal. Girls can expect anywhere from 20-40 days between periods, but some girls go months without a period and it’s completely normal. The World Health Organization did a study and found that the first menstrual cycle after a girl starts her period for the first time (referred to as menarche) can range from less than 20 days to more than 40 days. Actually 38% of healthy girls had cycles longer than 40 days apart.

What causes my period to be so irregular?

Most of the time, girls who’ve just started their periods are still maturing physically.  Most girls experience irregular periods for the first 12-18 months after menarche, because of this immaturity.  Sometimes this immaturity can actually cause heavy bleeding. After this period of time irregular periods can be caused by pregnancy, infection, the use of birth control, stress, bleeding disorders or other hormone disorders.

Some forms of birth control can make bleeding and irregularity worse, especially if not taken correctly. It’s not common to have bleeding between menstrual cycles (spotting) if you’re taking the pill, if you’re on the shot, the patch, the ring or have an intrauterine device or implant. It’s very important to take your birth control medication correctly, or you can have lots of bleeding between periods, known as spotting. Sometimes we have to ask detailed questions regarding how you take your medicine to determine if this is the cause of your irregularity. 

What can be done to make my period more regular?

Irregular periods aren’t harmful. Some girls wish to make their period more regular and ask how this can be accomplished. Birth control pills can be prescribed which help make hormone levels more normal, resulting in a more regular period but only if taken correctly. Again, if pills are not taken correctly, spotting can occur between periods making the period seem irregular.

When should I be worried about my irregular period?

  • Polycystic ovarian syndrome (PCOS) can be a cause of abnormal bleeding and irregular periods in young girls. Usually girls will also have other symptoms which suggest PCOS may be the cause. Symptoms include: obesity, insulin resistance, abnormal amounts of hair in strange places and acne. If you think you may be suffering from this, we’d like to do an evaluation.

  • If you’ve had your period for more than 5-7 years and you still have irregular periods, there may be a medical reason.

  • If you are sexually active you can get pregnant, which would cause an irregular period or no period at all.

  • If you exercise obsessively or eat very little, it can cause your period to disappear for a while.

  • If you’re saturating more than 6 pads or tampons in a day, you may be bleeding too much.

  • It’s uncommon to go more than 90 days without a period, so if that much time has passed with no period, we’d want to see you.

In any of these cases, we would want to see you in the office to do a more thorough examination to determine the cause of your irregular periods.