Runners - Hamstring injury?

JenRun1

I'm just curious if anyone has had a hamstring injury and what it felt like. I'm obviously going to the DR but for the past 4 days I'm in alot of pain when attempting to sit or attempting to stand. Once I'm up I'm fine. In fact, I ran 5 miles on Saturday and felt fine during the entire run. Once I'm sitting, I'm fine for a little bit but then the pain starts all over again. I'm a runner and not sure if this is just a pulled muscle or something more serious? Just looking for other stories similar to mine and if it is really serious enough to head to a DR.