I'm on day 17 of my period.

This is officially the longest period I've ever had. (I'm 26 years old) Normally they last about 5-6 days but this has been over two weeks so obviously, I'm getting concerned. (By the way, I am not on any birth control and not pregnant) And it's not by any means a heavy period, mostly light to medium flow with occassional clots (sorry to be graphic)
My cycles are very irregular too. I'll go months without having a period. But sometimes I do get one every month. I tend to alternate between having regular monthly cycles to having not so regular cycles)
I've been looking up other symptoms of pcos online and I have the facial hair thing (annoying chin hairs!), and I have a little acne, but I am not overweight as I only weigh 100 pounds. Although I do have concerns about my blood sugar (I think i have low blood sugar) but i don't know if that could be related in any way.
I guess I just want to hear from people who have this condition...i know not having your period could mean you have it, but is having a period that lasts for more than two weeks also a sign of pcos? Has anyone ever had a period that lasted this long? I just want it to stop!