There is no one definitive test that can diagnose PCOS. The diagnosis of PCOS is a clinical diagnosis, meaning the diagnosis is made by your medical history and not any specific blood test. Three criteria determine if you have PCOS: Irregular menstrual cycles since puberty (when not on hormones); signs of androgen excess (excessive hair growth, acne or an elevated blood testosterone level) and PCOS appearing ovaries by ultrasound. To have the diagnosis of PCOS you on need to meet 2 of the 3 above mentioned criteria. The fertility clinic doctor will generally use a variety of tests and check things such as your weight, hair growth, menstrual history, screening test for diabetes, endometrial lining and more to treat your PCOS.