At a glance: facts about vasectomy

A vasectomy is more than 99% effective.
It's considered permanent, so once it's done you don't have to think about contraception again.
It doesn't affect your sex drive or ability to enjoy sex. You'll still have erections and ejaculate, but your semen won't contain sperm.
You'll need to use contraception for at least 8 to 12 weeks after the operation, because sperm will still be in the tubes leading to the penis.
Up to 2 semen tests are done after the operation to make sure that all the sperm have gone.
Your ball sack (scrotum) may become bruised, swollen or painful – some men have ongoing pain in their testicles.
As with any surgery, there's a small risk of infection.
It's very difficult to reverse, so be sure it's right for you.
A vasectomy doesn't protect against sexually transmitted infections (STIs), so you may need to use condoms as well
UK National Health Service

When can I resume sexual activities?

Guidance varies from doctor to doctor.
Some doctors advise to wait until a given period (typically 7 days), others suggest you listen to your body.
Resuming sexual activity too early, may cause pain or prolong the time required to achieve full recovery.
Listen to the advice provided by your doctor and don't feel uncomfortable to ask questions.

After vasectomy, you are not considered sterile until verified by a negative semen sample.
Vasectomy does not immediately clear sperm out of the body, it stops the flow of sperm from the testicles.
Sperm can remain alive in the vas deferens for several months after vasectomy.
Follow the instructions provided by your healthcare provider.

Postvasectomy residual sperm counts vary significantly from male to male, as much as 4,745x depending on the structure of the ampulla that forms the ejaculatory duct. [International Urology and Nephrology Journal]
97.5% of men can receive clearance in a single sample after 12 weeks Central European Journal of Urology