8 months off the pill and still irregular periods

So I came off my pill (yasmin) 8 months ago, after a long 11 years on it.. i had my usual period after the pack finished, then one a month after it exactly- great I thought!! But then nothing for 3 months.. Then a month.. Then two months.. Honestly it's just torturous!! Anybody else having trouble with regular periods since coming off the pill? Worried I may have PCOS, had blood tests from my GP which all returned normal and now been told to wait until April then contact again then to discuss possibility of scan!