Small lump in wrist in my vein from i.v what is it?

See derm: This could be from trauma to vein and maybe a ganglion cyst. See dermatologist for evaluation.

Phlebitis: The vein used for the IV has a thrombus secondary to the irritation of the catheter placed into the vein along with the solution instilled. Usually, this is tender to touch, firm, and may travel up the vein. Most of the time this is self-limiting, and local heat will resolve the pain. Should it progress, and become red, hot, seek help of your physician.