The due date for irregular menstruation cannot be calculated from the last menstruation, but you can cooperate with your doctor for examination and determine the due date by checking the size of the fetus through ultrasound.
Generally speaking, the expected date of labor is 280 days from the first day of the last menstrual period. For women with irregular menstruation, there is no way to predict the due date from the first day of the last menstruation, so you can use ultrasound to check the size of the gestational sac, the time of the appearance of fetal heartbeat and fetal buds, and the diameter of the apex and buttocks, etc., to calculate the gestational week and know the expected date of delivery.
It should be noted that the expected date of labor may be advanced or pushed back, so we should carry out regular obstetric examinations, and if the development of the fetus is normal, we need to wait for delivery. If contractions do not start even though the due date has been exceeded for two weeks, immediate medical attention is required, and assisted interventions should be used if necessary.
It is recommended that women should relax, do not be anxious and nervous, maintain a balanced diet and nutrition, not picky and partial food.