Unwanted pregnancy problem. Test it?

Me and my gf age (23 years having a average cycle of 32-34 days  ), had an intercourse on February 28th(probably it will be on her ovulation day ) but I didn't cum inside ( pull out method ) but fearing pregnancy she took unwanted 72 ECP on the same day within 8hrs , her last period was on 9th February ( 1st day ) , but now she is experiencing a bleeding discharge from yesterday on March 13th ( 13 days after taking ECP ) ... We are really worried is it a withdrawal bleeding or any Implantation has occurred ??? If it's withdrawal bleeding when can we expect her next period ?? Can u plz tell us the date on average when will her periods start again ?? Or if she is pregnant and Implantation has occurred when do we have test it ? Very confused plz help us !