Theoretically yes but the increase would be so small you most likely wouldn't be able to get anyone pregnant. It would be like instead of having 1 drop of water in a glass, having 2 drops of water.
If you are on testosterone, your natural testosterone production and sperm production will be suppressed. HCG will not change that. There is a reason why every bodybuilder gets off their TRT when they are trying to get their wife pregnant.