Can your period be late after sex but not pregnant?

Yes, it is possible for your period to be late after sex even if you are not pregnant. There are several reasons why this can happen:

Ovulation Timing: If you had unprotected sex during the ovulation window (the time when an egg is released from the ovary), it is still possible for your period to be late even if the egg was not fertilized. This is because the hormonal changes that occur during ovulation can affect the timing of your period.

Stress: Emotional stress can disrupt your menstrual cycle, causing your period to be late or irregular.

Illness: Certain medical conditions, such as thyroid issues, polycystic ovary syndrome (PCOS), or infections, can affect your menstrual cycle and lead to a delayed period.

Medications: Some medications, such as birth control pills, certain antidepressants, or antibiotics, can alter the timing of your period.

Changes in Weight or Diet: Significant changes in weight or a sudden change in your diet can also disrupt your menstrual cycle and cause your period to be late.

If your period is more than a week late, it is a good idea to take a home pregnancy test or visit your doctor to rule out pregnancy and determine the cause of the delay.