I woke with a small hard lump on my leg, its painful with a burning feeling and getting bigger. any ideas please?

Lump on leg: Without an exam and a good history the guesses would be an abscess, insect bite, contusion/bruise, Boil, carbuncle, infected cyst, sebaceous cyst, folliculitis, and several other possible things. If it does not go away, get an eval of it.

Phlebits: Could represent superficial thrombophlebitis. This is formation of a blood clot in the superficial veins. Usually responds to warm compresses/heating pad and ibuprofen. More likely if you have a history of varicose veins, leg swelling, or spider veins