Hi, I am breastfeeding and am having 36 day cycles. I had unprotected sex the day before my expected period. The day of my expected period I had light Brown spotting. The next day I had light spotting again. Spotting ended completely on the 3rd day. I went to the doctor and got a prescription for plan b, but took it at about 78-79 hrs from the time of unprotected sex. Could I be pregnant?