Questions on injury

I wonder if anyone can help me here.. I have been experiencing some pain in my left shin during running and skipping at boxing. It's on the inside part of my shin and it hurts as I put my foot down and also to the touch if I press it lightly. I don't know if it's shin splints, can you get them in just one leg? And would they hurt kind of like a bruise if you touch them? I thought I had them before a few times and the pain was more towards the front of my shin and a lot sharper only when I stepped, this pain is like a dull ache. I'm just trying to decide whether or not I should be running tomorrow.. I really want to, I have my long run planned and if I don't do it I will only have run 3.9 miles this week which doesn't seem like enough! I have rested for a week a little while back and it didn't clear up, since the pain wasn't too bad I started up again, it's been bothering me since October/November time last year it seemed to clear up around December and then came back.. It doesn't hurt really badly I'm just concerned that it's not going away! Any ideas or opinions would be really appreciated thanks!