Cilest - light, brown period?

I have been taking Cilest for the past year - this month I had a stomach bug which caused me to miss one pill, I was able to take one the following day but again the day after that I missed. I had read the 7 day rule and to be extra safe did not have after that for about 8 days, there were about 13 pills left. I have left a break between packs but my period was much lighter than usual and more browny. I still have a a niggly tummy like I should be bleeding but not much is happening. When I have missed one pill before I have usually gone on to have a usual period. I'm a bit worried because I've never had this before, and the leaflet doesnt really say if this is ok, or if things should continue as normal after a missed pill - doe anyone know anything about this?