Medically reviewed by Sophia Yen, MD, MPH – Written by Pandia Health Editorial Team

NOTE: If you are 12 years old, your period won’t be regular for another 2 years!

Most of us have been there — you check the date on your period tracke app and realize you’re supposed to meet Aunt Flo today. But… she never comes; and then a few more days pass and she still doesn’t arrive. Seriously, the one time you want your period and it doesn’t show up?! There are many explanations for why your period is late. Check out our video on the top reasons why your cycle is taking longer than usual to start here!


This is probably the last thing you want to hear if you are actively on birth control in order to not get pregnant. However, this is one of the  first things you should check if your period is later than normal — if your breasts feel more tender and you’re experiencing nausea, it’s a good idea to take a pregnancy test. 


This is a biggie — 52% of Generation Z in the U.S. have been diagnosed with mental health issues and women are more stressed out than men. When we’re stressed, our cortisol levels rise, limiting the activity of progesterone; progesterone prepares the uterus for fertilization by thickening the uterine lining, or endometrium.

If fertilization doesn’t occur, progesterone levels drop so you get your period; if your progesterone levels were too low to complete this phase of the menstrual cycle, your period might be delayed. To get your period –and your life — back on track, start by identifying and eliminating the unhealthy stressors in your life.

Want to reduce stress and get rid of “pill anxiety”? Sign up today to get your birth control delivered for free — experience Pandia Peace of Mind and never run out of birth control again!

Birth Control

It’s normal for your period to get out of whack when you start a new form of contraception. If you’re on the pill, patch or ring, your period may become heavier, lighter, or come at a different time of the month than expected; after about three months, it’ll become regular again. If you have the IUD or the implant, it’s more likely that your period will either become irregular or you will lose your period altogether as seen in 70% of women who use these methods.

Learn how to turn off your period with Pandia — #SkiptheTrip to the pharmacy through our online birth control delivery service and skip your cycle at the same time! 

Not enough Calories 

If your weight has shifted due to changes in your diet and/or exercise, you may experience a delay in your period’s arrival or even amenorrhea which is the absence of menstruation. It has to do with low energy availability — when your body doesn’t have enough energy to keep your systems going, it takes energy away from nonessential ones like reproduction and growth. As a result, the hypothalamus slows or stops the release of the hormones that control ovulation which is enough to disturb your menstrual cycle.

Medical: PCOS

If the delay of your period is caused by a medical condition, it’s best to check with a doctor to make sure it isn’t anything serious. Medical conditions can include thyroid problems and polycystic ovary syndrome among others.

Hopefully your period has arrived by the time you have finished reading this blog post! If not, check the above tips for how to deal with Aunt Flo’s late arrival. While you’re at it, scroll through the rest of our blog for more resources on periods, birth control, and reproductive rights! 

Watch our CEO/Co-Founder Dr. Sophia Yen talk about the 5 reasons your period is late.


The above information is for general informational purposes only and is NOT a substitute for professional medical advice. Always seek the advice of your doctor/primary care provider before starting or changing treatment.