Tonight was my first night using the Gonal-F RFF Redi-ject pen. My pen is the 450 version. I read and preformed all the instructions but I didn't feel anything when I injected, and the dose amount was zero. When I looked in the reservoir it still looked full. So I did the whole process all over again with pretty much the same results, only this time when I check the reservoir it look like it had gone down some. (It was now at the 750 line on the reservoir) So I went and looked at another brand new pen where the reservoir showed filled to the 900 line. I'm am now afraid that I accidentally doubled the dose. My dose was supposed to be 75iu. Can any one tell me if the numbers on the side of the reservoir actually indicate how much is in there in iu? I'm confused though because a new pen looks like it is filled to the 900 line even though it is a 450iu pen. If anyone has had a similar problem or knows anything about what the reservoir number pertain to please let me know thanks