I had taken an ipill in March and had periods before my date that month for 3 days. My normal cycle continues for 5 days. The very next month , I had periods 8 days late and again it lasted for 3 days  provided I was exercising too. Then , for May I had paused my exercises for a while and had protected sex in May itself just a week before my periods. I didn't get my periods . It's 16 days late now. And yes, I have taken 3 pregnancy tests till now, it shows negative. What medication should I take? Also, i have hypothyroidism but that is also under control now! Is it normal to miss your period for one month for taking the ipill?