Had a ddimer yesterday negative. now today i have a serious bruise with a lump under it on the side of my calf/shin, no injury and its causing a ton of pain. can a ddimer be negative then the next day a dvt show up so suddenly??

That could happen. D dimer is not a perfect test. Did you have the d dimer test yesterday because of calf pain & tenderness or because of suspicion of a pulmonary embolism? Under the leg bruise the lump could be a collection of blood( hematoma) in the subcutaneous tissue from trauma or a spontaneous bleed and not a DVT. A physician can tell the difference by examining your calf. Get leg U/S