I wouldn’t really advise it myself. Once you mix hCG, even kept in the fridge, the potency begins to gradually degrade. By the time you get to week 3-4, it’s usually suggested that you re-mix a fresh batch at the point.
What happens is as the potency of the hCG degrades, now the hCG dosage that originally made you not feel hungry isn’t sufficient to cause the same effects and you can start to feel hungry and crummy on the diet and it seems that it can even start to affect weight loss from what people have reported.
If you choose to try doing this anyway, my best advice is to start increasing the dosage of hCG to compensate for the potency degrading, so that you will hopefully be closer to the effective dose you need in your system.