In your case, you still don't need the ultrasound tbh. You need clinical OR laboratory signs of hyperandrogenism (in your case, hirsutism) Coupled with absent periods, you have two features. As long as they don't suspect another etiology (which can be tested for via blood), you can be diagnosed.
In Australia you wouldn't need it because you already meet criteria. That being said the treatment doesn't really change wether you label it as PCOS or not - it's to go on hormonal contraceptives.