Clomid challenge is not a bad idea, to see if you are primary or secondary hypogonadism. Then go from there. That is the approach I would use if a patient would want to concieve before mocving on to TRT. If you are on TRT then hcg then test for sperm motility and count. If it is low then look to factors which may be causing it to drop. You be surprised of what can cause it drop like a rock. If sperm are low then add in HMG 75-225 ius a week then retest in 2-3 months.