Had my vasectomy 19 years ago, one month after my son was born. After the procedure and on the way out I asked the gal at the front desk, "when will I know I'm sterile?" The old gal said very business-like, "after 15 seperate ejaculations, take a sample, bring it in here and we'll test it." I said, "okay, see you tomorrow".................she didn't even look up or laugh. True story, I couldn't even get a smile.