Hi. I've been on Tricyclen for the past 7 months, i switched to it from Alesse. My periods have been pretty normal considering I have endometriosis. The Tricyclen's actually been making it so much better, and my periods have been way more predictable. I'm totally faithful to the pill, take it every night at approx. the same time. I missed I think 2 pills when I first started taking Tricyclen, but not since then. I usually get my periods on Tuesday or Wednesday, during the last row of pills in the pack, however today is Friday and still haven't gotten it. Could I be pregnant? Could I just be really stressed out? Maybe I'm sick? What are some reasons that this might happen..