Is this the first pill you have been on? If yes, myself and a lot of people I know have had various problems when on microgynon. I've found that most people are put on microgynon first (it's probably the cheapest) and then change when they have difficulties with it so far the problems I've heard of are--- recurrent thrush (my own problem)
really bad mood swings
headaches
sickness, so it could well be the microgynon.
Go to your dr as soon as you can and tell them about the problems you've been having, they'll probably want to run some tests but it's the only way they're going to be able to properly help, hope everything gets better! x