As a man, how can I get some measure of my current fertility?

Before assuming that you have lost fertility due to treatment or that you must now pursue alternative reproductive methods, it is important that you find out your actual fertility status.
For a man who has completed cancer treatment, there is a wide variation in the length of time it takes to return to normal levels of sperm production. For some men, it may occur within a year; for others, it may take up to 10 years or even longer. As difficult as waiting may be, it’s important for you and your partner to be patient.
A man’s fertility can be measured in a number of ways, but the ultimate measure is his ability to achieve a pregnancy with his partner.
If a couple is having trouble conceiving, a fertility specialist can help by testing a man’s sperm levels, motility, appearance, and shape, as well as measuring hormone levels (testosterone and FSH). These hormones can reveal how well the testicles are functioning to produce sperm.