I've only been taking Micronor for four months.. but on my third month I had exactly what you are going through. When I called my doctor freaking out she said not to worry in the slightest because the purpose of Micronor is to not have a period. Most likely your period will be about a week late because it's attempting to regulate your body. She said if I felt anxious to keep a few birth control tests and take one every few days, but that if the first one was negative that I was most likely not pregnant. And sure enough my period did come anyway. HUGE RELIEF!
So relax, I can't be 100% sure, but you can always call your doctor and schedule an appointment. But, I did go through the same thing.