is my turtle pregnant?

Question
i just got my turtle recently and i've noticed thatshe only swims on one side of the tank. it made a large  pile in the middle  of what she pushed aside. will she lay her eggs underwater. if they do will they be healthy and how many will hatch.  Shes a red-eared slider and could she have mated with another male at the store?

Answer
Swimming lopsidedly is usually a sign of pneumonia, and digging in the gravel is usually a sign of a crowded tank.

In either case, turtles never lay fertile eggs in the water. When they DO lay in the water, it is always a worrisome sign.

You might want to review the basic cares at a good site like http://www.redearslider.com and see what they suggest here.