I had sex on the 4th of the month, took plan b on the 7th and got my "period" on the 13th. I bled from the 13th to about the 17th or 18th and had sex again on the 19th. When I had sex on the 19th my partner pulled out. Is there a strong possibility I was fertile the day after bleeding? Is bleeding the week after Plan B considered a period or "withdrawal bleeding"?