And you've never done PCT for any of them?
LH is a signal sent by the pituatary to the testes basically telling them to produce testosterone. This is one distinguisher between primary and secondary hypogonadism - if the testes work fine, but the signal is week, that would be secondary hypogonadism. HCG replicates the LH signal, so if using HCG makes everything for you return back to normal, then you know the testes are not the problem, but basically, there was a signal disruption.
Clomid apparently can increase both LH and FSH (sperm production) as well as blocking any excess estrogen you may have from binding, so this could potentially work, again, only if the testes are operating normally and the problem is in the pituitary.
There could be any number of other things wrong, however, so blood tests and a doctor visit would be best.