how late should my period be before i worry

A period is generally considered late if it has not started within about 5 to 7 days after the expected start date based on a regular menstrual cycle. Most menstrual cycles last between 21 and 35 days, and occasional variations of a few days are normal. You usually should not worry if your period is just a few days late, but if it is more than a week late, it may be a good idea to take a pregnancy test if pregnancy is possible. If pregnancy is ruled out and the period remains absent for more than 10 days, or if late periods happen frequently, it is advisable to see a doctor to determine the cause. Other factors such as stress, weight changes, exercise, hormonal imbalances, or health conditions can also cause late periods.