I had spots when I was younger and I still have cysts on my ovaries, it's called polycystic ovarian syndrome. It's not life threatening although in the worst case scenario could leave you infertile (I've never known anyone with it not be able to have kids). Other symtoms include, irregular periods, excess hair on body and face, very painful periods and it can be harder to lose weight (but not impossible by any stretch of the imagination).
Losing weight can help the management of it but so too can the oral contraceptive pill dianette which I found to be fabulous when I was younger.
If any of the above sounds familiar then go back to your GP, ask for an investigation in to PCOS including a scan. It took a year or so for me to get diagnosed and I had to have one of those scans where they put the scanner inside you that looks like a big tampon.