I was walking into work and got a sharp pain across the top of my foot where the toes connect and it has been swollen tender nothing is broke had xray?

Cramping: This can happen without warning or explanation sometimes. If the pain is persisting or if there are more symptoms then a full podiatric evaluation may be warranted. But, usually this issue just subsides and resolves on its own.

Neuroma?: It is possible you have a 'pinched' nerve between the toes. Do you wear dressy tight fitting shoes- that would make this worse, do you feel an occassional click? Even though the x-ray was negative you could also still have a stress fracture. It will need to be x-rayed after 10 days.