How can you relieve pain after getting cervical cancer jab?

Ibuprofen. Procedures used to screen for and diagnose cervical cancer can cause cramping in many women. Taking Ibuprofen or another antiinflammatory drug (like naproxen) can minimize this side effect.
Pain Relief. Not sure what you mean by a "cervical cancer jab, " but but if you've had a leep or cryosurgery, there will be some residual pain which will respond to analgesics such as tylenol (acetaminophen) or a prescription pain reliever that your doctor prescribed. It would be best to consult your gynecologist for specifics in your case.