If you have shot up this batch of dope without a reaction before it is almost certain that you missed the shot in one way or another. When missing a vein the drug can be shot into a few different places. An artery shot is the worst situation with symptoms of bright red blood blowback into the syringe, extreme pain, tingling/numbness, major swelling in the extremities distal to the injection location, and requires immediate medical attention. If you missed all the blood vessels than the shot is likely sub-dermal (under the skin) assuming you didn't somehow stick it in a muscle. Sub-dermal shots are a legitimate way of administering a drug (known as skin popping) and result in a slightly raised bump (called a bolus) which is the drug as it slowly gets absorbed by your body. Sub-dermal shots are more likely to cause infection, abscess, and a localized histamine reaction (swelling and itching at the site) and can often be successfully treated at home with a warm compress, perhaps an antihistamine, and careful monitoring for signs of infection.
So what you are describing sounds like a sub-dermal shot in the wrist (smaller veins harder to hit). What compounds the problem compared to other injection sites is that the wrist has a lot of small hardware traveling through it as opposed to more muscle and large scale structures at more ideal locations. The needle, missed shot, and resulting swelling can all be putting pressure on and irritating nerves, blood vessels, tendons, and ligaments which are tightly bundled together in the wrist. Furthermore any movement of the wrist can just exacerbate it more.
As I said treatment is a warm compress for a few hours after shooting to ensure the drug dissolves, an antihistamine to help with itchiness, and some ibuprofen to help with the swelling. After a few hours you can apply ice and try to immobilize the joint and the swelling should go down overnight. You then need to closely monitor the injection site for any signs of infection, abscess, or any other situation where things get worse.
edit: If you suspect an artery shot then you need to go to the hospital immediately.