Woken at 1am with stabbing pains in the back of my thigh about every minute or 2. still going on, no swelling or redness. sciatica? worried about dvt.

Maybe muscle spasm: First, if pain is new, did you do anything differently prior to the onset of the pain, such as lifting heavy things or twisting with heavy weight or any extremes of movement? Any other symptoms like numbness/tingling, weakness, trouble walking or urinating etc? Isolated thigh pain is unlikely sciatica. More likely muscle spasm etc. Blood clot needs ruled out but again unlikely if no risk factors.