/random is very weird...

so, for some reason, when i run /random, it often seems to stick to the same number for a few seconds. heres an example: 
i roll a number from 1-3
i get 2. 
i roll again within 1-2 seconds
i get 2 again.
i roll 1.
roll again.
i roll 1 again.
is this a bug? or just how /random works? or am i just really unlucky/lucky?