I had protected sex on March 30 and took the ECP on April 1 10:45 pm (fist dose) and April 2 10:45 am (second dose) just to be sure because I was still paranoid. I am currently experiencing withdrawal bleeding (brown discharge) on the day that I should have my normal period (April 7). Could this be a strong sign that I'm not pregnant? When will my real menstruation occur?