Doing Human Chorionic Gonadotropin (HCG) 3x a week is silly. It has a biphasic pattern. So when you do a shot of Human Chorionic Gonadotropin (HCG) it stimulates testosterone production initially, but then the testicles go in to what is called a refractory period for 72 hours. So that shot 48 hours later goes to waste.
Also, 250 IU of Human Chorionic Gonadotropin (HCG) is a waste of time and money IMO. I highly doubt 250IU does anything at all when your injecting exogenous testosterone. it takes 600IU a week to get most men up to 600ng/dl for monotherapy, so your gonna need more than that when introducing exogenous T.
Sub-C or IM? It doesn't matter so go with the less intrusive injection, Sub-C