I drank a glass of milk that smelled like rotten eggs!?

I bought 2 gallons of milk (expiration date 3-6-07) last week and brought it directly home from the store. I am pregnant and was craving a glass of milk so I literally chugged a glass down! After I was finished I was overcome with the strong after taste of rotten eggs! I smelled the gallon of milk and it did not smell sour but a strong rotten egg smell. I threw that gallon out and opened the other one to find the same horrible smell. I wonder if there was something wrong with the cows? Do you think the milk can cause listeria or other food bourne illness that could harm my baby? Do you think I should contact Dean Milk or Meijer to find out what went wrong with the milk? The milk was not left out of fridge! haha what are my milk rights!