Yes, if hormonal blood tests are normal and there's no obvious signs of hyperandrogenism (in your case, the hirsutism seems subtle), then that's when ultrasound comes into play. Your GYN did a laparascopy and visualized the ovaries directly, which would replace the ultrasound in this case. Also, women with PCOS tend to have skipped or absent periods, not prolonged periods. So, I can see why your GP would be skeptical.
Sorry to piggyback this comment but just out of curiosity, can PCOS ever be a possible diagnosis even if hormonal blood test results indicate otherwise? I have always some of the physical symptoms (long periods, cystic acne, mild hirsutism), and my consultant gynaecologist diagnosed me with having PCOS after observing that my ovaries were enlarged and pearly during a laparoscopy to excise endometriosis. But bloods I had taken when I was much younger, and further bloods I had taken 2-3 years after this surgery showed that my androgen & testosterone levels were within normal ranges, so my GPs opinion is that I dont have it (regardless of my consultants observations). Ive never quite known what to make of this difference in opinions. Any thoughts?