I would lean the other way and say no...this probably isnt MS. The fact that you have to push on it for it to happen, is more than likely a nerve which is trapped or pulled.
MS pain is constant in areas where there is damage. If a lesion in your brain was presenting in your foot (which is possible), you would have constant pain, even if it were for only a few hours or days...not "only" when you push on it.
One of the toughest parts about having MS is learning what is, and what isnt, MS related.
Think back, did you do anything in the past few weeks which could be causing this pain? Bump your ankle? Run? Walk too far? Wear boots where something was rubbing up against that part of your leg? Does Ibuprofin help? Does heat or cold help?
If anything helps, its not MS related in most cases...
I would also see your GP and ask to have a CT scan of this...chances are its a nerve- MS wont show up on a CT scan.
I do hope you feel better soon....and as the old adage goes "if it only hurts when you push on it, DONT push on it!"