Missed Periods – You go to the bathroom, pull down your underpants and… nothing. You expected your period to be here by now, but it’s not. Before you start to worry about why it could be late, take a deep breath and read this.
Your body is not a clock, and variation in your menstrual cycle is normal, especially if you are a teenager, breastfeeding or nearing menopause. Stress, travel, diet, illness and medication (including birth control) can also affect your cycle length, symptoms and the length and heaviness of your period. Up to 7–9 days of variation cycle-to-cycle is considered normal for adults.
If you have a regular menstrual cycle (for example, your cycle length rarely varies by more than a couple days), then you are only at risk of pregnancy if you had unprotected heterosexual sex or had a high risk of sperm touching your genitals during your fertile window.
How to Get Rid of Irregular or Late Periods
This is the six days leading up to and including ovulation, usually around the middle of your cycle (note that the fertile window displayed in Clue is only an estimate — your actual fertile window might have different timing, which can vary cycle-to-cycle along with the start date of your period).
You can take a pregnancy test about two weeks after your estimated ovulation day, but the earlier you take a test the less accurate it may be and some brands are more sensitive than others. You should probably take a pregnancy test or contact your healthcare provider if your period is nine or more days late. source, helloclue