The gestational sac is between 0.5-2.5 cm and is suitable for a medication abortion. It is likely that you are between 35-49 days pregnant at this time. If the gestational sac is too small, the hormone level is relatively low. It is less sensitive to the medication and can easily cause an incomplete abortion. However, if the sac is too large, more than 2.5cm, it means that you have been pregnant for a longer period of time. If you abort with medication there is a risk of haemorrhage and sometimes incomplete abortion, so you should choose between 0.5-2.5cm of the sac. Basically, it is safer to do it within 49 days of menopause. The chances of having a complete abortion during this time are higher and the bleeding is less. The safety factor is greater and the chances of another abortion are less.