math.random with tables seems to be giving similar number after picked?

I have a round-based game I was working on and sometimes you can get special rounds. I pick them out using this:

Chance = {1, 2, 3, 4, 5}
Choice = (Chance[math.random(#Chance)])

if Choice == 1 then
   -- do something
elseif Choice  == 2 then
 -- do something else

-- and so on

Although lets say "Choice" happens to be 2. If it picks 2, it seems like it picks 2 more often for a few turns. If it were to pick one, it'd pick one more often for a few turns. I was wondering if there was a better way to do this or if I just happened to be getting the same number a few times in a row.