Could very well be shin splints, if so you'll have have to give it a rest for a while.
New or better running shoes may be required.
You very likely have shin splints (although only an orthopedist or other healthcare professional can verify).
If you search my journal, you will see that I hurt my left shin in February '09. I did two triathlons, including a half Ironman with this injury, but did not become painfree until August after resting the legs for 2 full months and getting orthotics.
sounds to be most likely shin splints. i also had the same problems and symptoms. i for my job have to run alot. i develpoed shin splints about a year ago and when i was away at training i was running everyday, i was having this same pain. i was not aloud to stop running so i had to run through. the pain was unberrable but got so bad it caused a stress fracture in my left tibula and stress reaction in the fibula. i would rest and get it looked at. i have still not recovered and its been 6 months so take care of it now. ICE ALOT, TAKE IB PROFEIN, MOST IMPORTANTLY DO STRETCHES!!! its very painful i kno but you don't want to take the injury further like i did. and get some orthotics for your shoes i had custom ones molded to my feet from my doctor try that they work wonders
stretch your calf and the muslce running along your shin really well before you workout