When I'm working out regularly, I have no problem bench pressing and doing flyes, so I know my pecs aren't particularly weak. Yet, I can't do a single push-up. MAYBE 1 or 2 on my knees, but that's it. Obviously, there are other muscles being used aside from the pecs, or my form is bad. I figure if it's that difficult to get good form on an exercise, then it's not such a good exercise, and I leave it out.
-Nancy