poking belly, pain???

Curious about something.  I usually don't go around poking on my belly but I noticed today that at one certain spot it's very tender.   Move over a ½inch and nothing.  Last week I had a couple of instantaces of really sharp pain right about the same spot but nothing since then.  I am going in for a CT scan on Thursday so hopefully I'll find out what is causing my problems.  I was just wondering if you can feel something wrong by poking.  I've haven't had any disease activity in that particular spot.