HCG is best utilized during cycle and prior to pct.
It would help to know what you're cycling off, how long you were on, dosage levels and frequency.
Here's a common pct regimen (this is by no means written in stone as the best way to do it):
clomid 150 /100 /50 /25 / 0 / 0 / 0
nolva 20 / 20 /10 /5 / 0 / 0 / 0
aromasin 6.25/ 6.25 / 12.5 /25 /25 /12.5/ 6.25
Here's a link to a PCT calculator that shows levels in your system based on injection times and when to start pct.
I'm sure the proper pct start time is highly debatable and experienced guys know what works for them.
PCT Calculator | Post Cycle Therapy Calculator
Again, nothing I've said is written in stone.
Please do your own research. There is loads of information on pct out there.
Read a bunch of it, see what the majority are saying and formulate your own plan.
Once you have a plan, post it here and ask for tweaks and feedback.
Always have your pct regimen and gear on hand BEFORE starting a cycle.
Cycling off without proper pct is like driving a car with no brakes...