I dropped my MacBook from 50 cm height

help, i'm really freaking out, i accidentally dropped my macbook pro unibody 15' inch, procesor 2.4 Ghz intel i5, (just 6 months old) i dropped it with position left first, it's startup just fine, but then i realize, theres bump, and scrapping, but what concern me most is the bump that shape like small circle in the upper left of my speaker (the lid is closed when i dropped it) and i realize the back lid (where the screw are attached) is like missplace, i almost can see a gap there, i try the power adapter, the battery, usb port, ethernet, startup disk( i turn it off and on several time) verivy my hardisk, trying every key, lcd , speaker,and back light, but it just work fine too me.. no weird noises, but i still freaking out especially strange bump/dent that shape like circle.. i'm afraid there's long lasting damage, wonder how much will it cost (i'm just a freelancer)

what should i do.. answer pretty much apreciated.. thank u :)