Had a fall yesterday & on blood thinner. did not hit my head i went down & fell onto my leg and behind, my hands caught a rail & took some impact. do i have any concerns being on thinners & my leg being in so much pain? or more so if you hit yourhead?

Yes, deep bleeding with the formation of a hematoma is relatively common in such situations, not to mention pelvic fractures, always possible. Would suggest being timely examined ( either your doc or an urgent care office) for proper diagnosis and treatment.

Bruising becomes far more intense when using anti-coagulants. Your leg pain could well be secondary to the trauma, which could involve any structure. Have your doctor evaluate if symptoms persist. See no rationale to fret about head injury since that part was not injured.