You can safely use Mifepristone and Misoprostol pills even if your pregnancy is under 6 weeks . Keep in mind that if it is very early it may be more difficult to assess whether or not your symptoms of bleeding and cramping are consistent with successful abortion.
 Nathalie Kapp, Maureen K. Baldwin and Maria Isabel Rodriguez. Efficacy of medical abortion prior to 6 gestational weeks: a systematic review. Contraception, 2018-02-01, Volume 97, Issue 2, Pages 90-99. Retrieved from: https://www.clinicalkey.com/#!/content/playContent/1-s2.0-S0010782417304389?returnurl=https:%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0010782417304389%3Fshowall%3Dtrue&referrer=https:%2F%2Fwww.ncbi.nlm.nih.gov%2F