Why are my legs aching? Opinions please!

[xStarGirl]

For just over a month now, I've had mild to severe aching along my shin bones on both legs. It's alright when I'm sitting down, but if I'm stood for any length of time it starts up again.

As a bit of background, it essentially started after I did some very heavy walking over a few days. I've also started doing small, daily sessions of exercise to try and get into shape, and at first thought it might be due to my legs not being used to moving so much But surely if it was that, it would stop after more than a month? It's making exercise very difficult and more painful than it was already, and is doing nothing for my motivation

Do I need to go to a doctor? I'd feel silly going into my GP and telling him my legs were aching, but then what if it's something that needs treating?
Gaah. Opinions, anyone?

Shin splints, maybe?
Try looking it up, see if the symptoms match what you have?

If it is shin splints then it can be aggravated by fallen arches/flat feet and you can get insoles/special running shoes (fine for walking also) to protect them. I suffer from this and it means I can't do much walking/running. Cycling is OK, for some reason, if you're interested in doing that instead, and also swimming. More walking will make it worse though and you'd need to rest it as it can do permanent damage.

Ooh, reading about it that does sound right. Particularly because it can be brought on by exercise after a long period of inactivity. I don't have flat feet or fallen arches (I don't think!) but my feet do roll inwards slightly when I walk, which may have something to do with it.
Will have to stop doing running for a while, I think. Might break out the old bike! Thanks!