[FOUND SOLUTION] Are these pet chances broken? (pet system)

I feel like there's something wrong with the local Chance. People have been reporting that the pets that are under 1% are very hard to hatch. If I make it (0,TotalWeight) I'm pretty sure it won't work. Anyone can tell me if it's broken?

function ChoosePet(Egg)
    local Data = Eggs[Egg]
    local Pets = Data["Pets"]
    local TotalWeight = 0
    for i,v in pairs(Pets) do
        TotalWeight = TotalWeight + v.Rarity
    end
    local Chance = math.random(1,TotalWeight)
    local Counter = 0
    for i,v in pairs(Pets) do
        Counter = Counter+v.Rarity
        if Counter >= Chance then
            return v.Name
        end
    end
end