I had a vasectomy 2 months ago. i have ejaculated 32 times. i took in my sample and no sperm were seen. they said i'm not considered sterile until i bring in another sample in a month. what is the reasoning for this? is it necessary?

By CDC, ejaculation 32 times post vasectomy is not a reliable indicator. The reason for at least 3 months: the time to azoospermia varies widely in different studies; however, by 12 weeks after the vasectomy, 80% of men have azoospermia, and almost all others have rare nonmotile sperm (defined as ≤100,000 nonmotile sperm per milliliter). Failed rate 1/2,000 even you are considered azoospermia.