My insulin pen would not pass the flow check

I was getting ready for an injection and noticed that no insulin was coming out during the flow check.

At first I was not sure whether the pen was faulty, the needle was blocked, or I was doing something incorrectly. I do not want to waste insulin, but I also do not want to inject without knowing the pen is working properly.

For people who have faced this, what steps did you take when the pen jammed or no insulin came out during the flow check?