What's your diet like? If its mass you are after then you need to see what adjustments you can make to your diet. Winstrol hardens your muscles and may add minor mass but nothing spectacular in my opinion and experience.
Some folk use HCG right through cycles especially with AAS that shuts you down hard. Personally I think it's better to use it when you start your PCT because natural shutdown doesn't bother me or my business. So it's personal choice I reckon. I'm on my 4th tren cycle (cutting) and 3 weeks HCG...