No.

Most all bows have the string off center on one limb or both as you noticed. Some companies compensate for this by machining thier risers offset or like Mathews does hang their limb off to one side of the riser more than the other.

If you want to find the true centershot then you need to get one of the many different tools made for this task.

Another way to do it is to if you got a yard stick, or any other long straight edge, place it on the side of the riser (where the accessories attach) and measure the distance from the stick to the arrow at the string and then adjust until the point of the arrow measures the same.

Yet another way is to just eyeball it. Nock an arrow and looking from the rear align the string of the top limb so it bisects the center of the limb right where the two tips come together to form the solid part of the limb. Adjust the rest so that the string, center of the top limb at the top, and the tip end of the arrow are all aligned.

Actually if you are right handed it is good to go ahead and have the arrow pointing slightly left of center (looking from the rear) because you are almost guaranteed to torque the bow to the right a bit.