Everything is working then, it just seems to take longer.
Now first of all this could be a perceived lag, just like people say they can "feel" the difference of an aftermarket air filter or that octane booster that did not even raise their gas from 87 to 88 octane.
Here are the two items that could cause an actual delay in startup due to a drop:
Bad HDD - you would hear clicking and/or it would be louder spinning up. This usually results in overall slower performance though.
Slight damage to motherboard - would cost $300-500 parts&labor to fix
Cable/add-on card became slightly unseated - this would require a disassembly of the laptop and going through all the cables. This is something not for the novice and would run you $50-150 depending on the shop (and frankly if the $50 shop has no qualifications I would be highly skeptical).
So bottom line, if that is the only problem the computer is having I would let it be.