You could get a blood test.
What makes you think it's not legit?
If your boys are slowly growing back to normal size, that's a good sign that I notice about 1 1/2 weeks into PCT.
Otherwise, if your nips are flaring up, you may have a bunk SERM, since that's one of the main things it prevents I suppose that would be an obvious symptom. No way to truly know without blood test though