You don't say what year your car is, I've dealt with the same issue in 88-91 civics. I think it is your fuel pump relay. Get up underneath your dash, and if you look right above the handle for you hood release, you should see a relay and some wires going to it. Reach up there and wiggle it next time it won't start (there's a little opening in the plastic underdash trim piece, coincidence?) and see what happens. I kept my roomate's 91 hatch starting for months this way. Also try turning the key to the on position and get a helper to lay down on the ground on the driver's side and see if they hear the fuel pump whir for a few seconds when you do that. If you don't hear the fuel pump whirring, then it's your relay, pump, or the wiring.