You should be using Nolvadex concurrently while using HCG. Gonadotropin(through the Pituitary)will cause your Testes to produce Estrogen as well as Testosterone. That's why Arimidex and Letrozole are not suitable during HCG therapy... the Estrogen hitting your body right now didn't come from aromitization of Testosterone... it came right off your balls as Estrogen.
I've used HCG to finish off my last 3 cycles. I do one 5000IU IM injection/week for 3 weeks(15 000IU total). Run 20mg/ED of Nolvadex concurrent during those 3 weeks... then do the 'boiler room' Clomid regimen. During those 6 weeks is when I'm the strongest/hardest of my entire cycle... works like a charm.