You can get pregnant again immediately after doing the medical abortion. It is very important to start using contraceptives as soon as possible. The contraceptive pill can be started on the first day of the first normal menstruation after having the medical abortion (and after that as well of course) . Condoms can be used immediately. An IUD can also be put in place by a doctor during the first normal menstruation after the medical abortion. (and after that as well of course).
If you do want to become pregnant again after doing a medical abortion, it is also better to wait until after the first normal menstruation, so please use contraceptives until then.