That's great that you're going to the doctor, as it is better to be safe than sorry as the saying goes.

If you're over 40, you could be going through perimenopausal symptons. I've had the problem of spotting or irregular bleeding between periods for about 2 or 3 years now, although it has tapered off in the past few months. Doctor did a biopsy twice (OUCH!!!!!!!) but it was normal. I'll be 47 soon, and this is the only explanation they have since they find nothing wrong.

I'm not sure if that is a sympton of a cyst, it could be.