Spotting

[asbayford]

Hi!
I have very irregular periods (my last one was 110 days ago. I've noticed ever few weeks I get very light spotting (brown) for about 3 days (like a period is about to begin) but nothing comes of it. I'm not pregnant or sexually active. I do have cysts on my ovaries but they are not sure if I have polycystic ovarian syndrome. Drs seem very funny about diagnosing me with anything. Lots of scans done too. I was just wondering why I spot but no period starts?
Edit: I'm 29 years old

[Mr. Hugh Byrne, MRCOG]

Yes this may be PCOS so I would advise blood tests as well and referral