I have a bruise above my ankle but have not hit anything/lower leg hurts

Go see a doctor immediately!

Deep vein thrombosis (also called DVT) is a blood clot in a vein deep inside your body. These clots usually occur in your leg veins. While DVT is a fairly common condition, it is also a dangerous one. If the blood clot breaks away and travels through your bloodstream, it could block a blood vessel in your lungs. This blockage (called a pulmonary embolism) can be fatal.

http://familydoctor.org/online/famdocen/home/seniors/common-older/800.html