I am 24 and already have recurrent joint pains, so what could it be?

Might be nothing... Many people have the mistaken notion that they will never feel pain. Possibly, you are experiencing normal achiness related to work or to an exercise program. If, however, your pain is frequently disabling or is accompanied by significant swelling or stiffness, you might have a more significant illness. Discussing such issues with your internist, or even with a rheumatologist, may clarify things.
Important question. As noted this may or not be arthritis but if it is we like to see you as soon as possible. The earlier we see and diagnose arthritis the better your long term outlook is if you have arthritis. Other types of arthritis, nonarthritis, bursitis and tendinitis might explain your symptoms. It needs clarification whatever you have.