Sore lump in my lower left stomach area..

I dont know if this is something to worry about but...

I have what feels like a golf ball size knot in my lower left stomach (not the port site). I'm a week out of surgery and I've been moderately active...nothing too strenuous. The other night my fiance (who has PTSD from the 14 months he spent in Iraq) had a nightmare and whacked me in the stomach...pretty close to where this knot is. Not sure if that is a coincidence or not....

Its sore, but not unbearably painfull...