i just restrung my tbird and now theres a buzzing whenever i hit the string while on a fifth or lower fret....

that doesnt always work. if the gauge of the strings was diffrent from what you have been using, your neck will bend and you will need to ajust your truss rod and then raise or lower your action
How many winds did you leave on the tuning peg? If you cut the string too short and don't leave enough winds, on certain basses where the headstock doesn't bend away from the beck (i.e. Fender basses), this will cause the string to buzz slightly.

You could have the winds below the string instead of above.