DESPERATELY NEED ADVICE!

I am starting a 15 week cycle of 500mg Test E in the next few days. My supplies arrived today. However, I am a bit confused over the correct usage of the HCG.
I am going to administer 250IE EOD throughout my cycle until PCT starts, so I bought 3 vials of 5000IU in powder form.

Now, my question is, that each vial of HCG came with an ampoule of 1ml sodium chloride (0,9% w/v), so I have a total of 3ml. I read on most forums that for a 5000IU HCH vial, you would need 5ml of dilutent. Is that true? Obviously once I mix it, I will keep it refrigerated. Should I just inject the entire sodium water into the HCG and mix it that way? Will that be enough or do I need anything else? More sodium chloride?

Also, I read that reconstituted HCG only lasts for 30 or 60 days. So after mixing, It should not go bad right? One vial should last me 40 days. Can I just leave the other two vials (in powder form) in a drawer until I use up the first one?

Thanks!