I wouldn't worry, You might have just pulled something slightly and the muscles are cramping around it.
Go lightly for a day or so and see how it still feels. Though obviously if it gets worse then go see a doc ASAP.
42" jeans(25/01/2013) 40"(28/02/2013) 38"(20/03/2013) 36"(25/05/2013)
Down from 60" waist jeans since June 21st 2012.
Mini-goal: Lose as much as I can between now and November 27th when I fly to Florida!
Goal maintain between 224 and 210 until Jan 1st 2014.
St Paul's Cathedral - Climbing to the Whispering Gallery and Beyond!
Florida for a friends wedding and Themeparks!
Onwards and Downwards! http://www.menu52.com/