Had sex then used plan b and a heavy period one week later... since I have not had a period for 6 months and suspected menopause. Something about plan b had started my cycle again instantly. Then one week after my first period I had unprotected sex followed two days later by anther heavy period. Very odd- I was going to take another plan b but that hardly seems necessary as I can't imagine how I could be pregnant wth repeat uturan sheds. However the ovulation after a first period would be close enough to think again- could I be ovulating and having a period?