###Human: Took Unwanted 72 and bled after 13 days. Is that implantation bleeding or withdrawal bleeding? ###Assistant: Hello. It is likely that she has got her withdrawal bleed which can be seen in next 7 to 10 days to post unwanted 72 intakes, however, implantation bleed occurs in next 2 to 3 days and it is often spotting to scanty bleeding and not in the good flow. This can be confirmed by getting a serum beta hCG test (human chorionic gonadotrophin test) done which can conclusively rule out pregnancy as well, earliest by 10 days post intercourse. If the hCG levels are less than 3mIU then she is surely not pregnant and the bleed is not an implantation bleed(as it is always a retrospective diagnosis). She would get her menses now only after a month counting from the day of the start of the withdrawal bleed as this bleed marks the day one of the starts of a fresh cycle, for sure her dates would be changed now.