How do I know if I have pcod?

Won't always. Pcod is a clinical diagnosis so you may figure it out fairly easily. Irregular cycles, evidence of elevated male hormones, and evidence of pco on ultrasound. Male hormone effects range from facial hair, acne, oily skin, scalp hair loss and different people have different symptoms. Not all have very irregular cycles. Need other testing to rule out other diseases. See your doctor for evaluation.