Eastling,
Some Q's
Now that you've seen it, is it getting bigger, smaller, staying the same?
Is she happy with you handling it - eg holding it, pressing it?
How "solid" is it - rock hard, or squeezable?
Presume this is a breeding sow not meat pig, and how old is she, and state of any pregnancy?
How tolerant is she in herself of you doing stuff to her?