You sure you have PCOS?

Alex
I saw a Dr a couple years ago who suspected I had PCOS since my af has never been on a regular schedule. She sent me to get lab work done which came back negative. My current Dr said that the blood work is not a reliable way of being screened because it has to be done at a certain time in your cycle. Which would be nearly impossible to predict with me because they're all over the place. She suggested doing all ultrasound of my ovaries to look for cysts. I'm considering getting this done but was wondering how has everyone else been diagnosed with PCOS?