Congrats on your pregnancy! I agree that your symptoms could be signs of pcos. Of course, there is no definite way to tell without tests. I would bring it up to your doctor again.
As far as pcos and m/c goes, unfortunately we do have a higher rate of m/c than your average woman. However, this does not mean that you will definitely m/c!!! Many women with undiagnosed pcos have 1,2,3 children without even realizing they have the syndrome. This is really a syndrome that effects women completely differently. The fact that you are 9 weeks pregnant already and things are going well is an extremely good sign! However, you still may want to talk to your doctor about the concerns. And if s/he does not listen, make them listen. Being on a medication called Metformin can lower m/c rates in pcos women quite substantially (to pretty much the same rate as women w/o pcos). I don't know if they can start you on Met while pregnant or not, because most women I know start prior to pregnancy...but it's definitely worth having that talk. But again-to restate-having pcos does not guarantee a m/c. Have your doctors checked your progesterone levels at all? Many women with pcos also have problems with too low progesterone. Even if you aren't diagnosed yet, you still might want them to check that level.
Congrats again on your pregnancy
p.s. If you do have pcos, try to stay off the web. Like anything else, the web gives you all sorts of info, including worse case scenarios. I find it especially helpful to avoid doing research on the web during pregnancy and getting my info straight from doctors.