Usling insulin syringe with the Novalog Flex Pen

[msu16366]

Well since I dont have the needles for the Nova Log flex pen the guy I got it from said I could just stick a insulin syringe into the pen and get it that way. I just want to make sure I am getting as many units as I want.
So the nova log flex pen is 100 units per ml. I just put the normal insulin syringe in and draw out 4 units correct.
I am pretty sure thats correct but I remember doing my HCG that the units on the insulin syringe where way different than what it said.

[msu16366]

Also doing it this way I will be able to aspirate