Pregnancy is counted from the first day of the last menstrual period and abortion is usually possible at around 42 days, 20 days is too short a time. Whenever possible, you should go to the hospital around 42 days of pregnancy for an ultrasound to rule out ectopic pregnancy, as not all pregnancies are intrauterine. When an ectopic pregnancy is present, there is no way to abort it, but rather to treat it surgically or conservatively depending on the condition. If the pregnancy is determined to be intrauterine and the gestational sac is around 1-2 cm, abortion can be performed at this time. If it is too small, it will result in an ineffective abortion; if it is too large, it will result in an incomplete abortion and may even make the chances of residuals much higher, again causing more and more damage to the uterus. Therefore, abortion should be performed at 45 days of pregnancy if possible.