Can misoprostol abort 3weeks pregnancy?

Yes it can: Misoprostol can abort an early pregnancy. it is less than 100% effective and is less effective than the combination of misoprostol and mifepristone. Whether you take one or both medicines, you need to be seen again two weeks later to be sure that the abortion was complete and that all is well.

Yes: Yes, a medical abortion can be induced with miso alone and it is about 85% effective. It may take several doses to complete the abortion to be successful and there is a small risk of bleeding that may need medical or surgical attention. In places where services for abortion are few, this is the only option for some women. http://iwhc.org/resource/abortion-self-administered-misoprostol-guide-women