hi,i also have had no period for 21 months,i had a colposcopy done the year this all started.i was on the pill and my periods stopped for four months then came back.my doctor changed me onto cerazette and i had same problem i later found out this pill can cause no periods.i have now been off the pill for two months and still no periods.i have had a lot of stress over the last few years and i also been tested for various things including menopause and all tests were negative.im 43.i keep being told not to worry but its always on my mind.let me know how you get on.