Micronor and Irregular Periods: Understanding Potential Pregnancy

Question
I have been on Micronor for the last 3 and half months. My periods have been very regular (5 days on period with a 28 day gap until the beginning of my next period). My last period began on April 2 and lasted unusually long (13 days). As this period was so long I predicted my next period would be occurring around the 16th May (28 days from the end of my last period). I am now 9 days late and was wondering about the chances of pregnancy? I had some light spotting about 2 weeks ago that only lasted about an hour (implantation bleeding?) and I have had cramps as though my period is about to come on but it never does. I also have a lot of cervical mucous and tender breasts. I have taken 3 HPTs but all negative. Please help!

Answer
We count a cycle from the START of one period to the START of the next period. Never, from the end of one to the beginning of the next. Remember that Micronor is a Progesterone- only  pill and can give you longer than usual periods. As long as the period is less than 14 days in length, it is considered normal.If your last period starterd on April 2, you should have started your next period  on  April 29. By now, you should have taken a pregnancy  test. If the test is negative, you should consult your doctor.