I took microgynon for many years with no side effects at all, but that doesn't mean you won't experience any.
Mamya is right, it does seem a little soon. I'd go back to your GP and tell him what you're experiencing, it may be harmless, or else they could look into changing your pill, there are many brands out there. I'm on Cerazette now and have been for years because it stops periods. I was swelling like a balloon and vomiting with pain every month. The lack of periods is bliss for me!