I got hit on the inner thigh and sustained a pretty bad bruise, after about three weeks, the bruise is gone but now i have a sore hard bump there?

Hematoma...: What you describe is a hematoma. A hematoma is a collection of blood, usually clotted, outside of a blood vessel that may occur because of an injury to the wall of a blood vessel allowing blood to leak out into tissues where it does not belong. A large hematoma can sometimes take a couple of months to resorb, and rarely may need surgery to resolve it.