Yeah, are you tall? I am and I get those all the time. Usually its the signal of either too much work, or dehydration. Eat a banana and some Gatorade then a ton of water. If it keeps up, get a lacrosse ball and while sitting on the ground put the ball under your calf, and push you leg down on the spot. Sometime your muscles get bunched and need some help.
The doctor may also arrange for you to have a blood test called a Doppler test.
This is to examine for deep vein thrombosis.
It is always best to get it checked out to put your mind at rest and also get the appropriate medication if this is required.
Hope all goes well.