Hello Ladies! So, I am in the process of doing my first IVF cycle. And this is all really new to my husband and myself. My question is how do I know when the Follistim Pen is empty? I know my nurse said it will stop but my problem is on the box it says 600. And I have been doing 225 for 3 days and today I did 150. But every time I give myself the shot it hasn't stop once. I know there are overfills but I feel like this is too much and I should switch the cartridge out. Confused... And I just hope I haven't messed something up. Any advice?