With early treatment of menstrual regulation, the probability of performing an unnecessary operation in quite high. Pregnancy tests available that are sufficiently sensitive to confirm an early pregnancy are beyond the financial reach of many clinics and hospitals. It is difficulty to justify performing procedures for patients with relatively insensitive negative pregnancy tests. However, there are occasions where the procedure must be done without delay. The total number of women considered was 14,716 of whom 12,888 reported a delay in menstruation of 1-14 days and 1828 reprted a delay longer than 14 days. Urinary pregnancy tests were done for all. The uterine aspirate was examined for pregnancy evaluation. The false positive rate was 7% and the false negative rate 42.3%. The probability of pregnancy increased with the time of delay in menstruation. At the end of the 3rd week of delay the probability of pregnancy was about 90%. Repeat curettage for heavy bleeding or retained products was the most serious complication. The rate of significant complications was twice as high when pregnancy was present. Of the 12,888 reporting menstrual delay not over 14 days, 29.1% were not pregnant and 3.9% had significant complications.