Not Receiving Achievements

Hello, so I've been playing on my realm for a while now. At least 60 hours worth. I was playing with some friends when they decided to achievement hunt. It was at this time that I noticed I haven't received any past Taking Inventory or Cow Tipper. I've done far more than just those two things. It's a survival realm with no cheats or anything so I don't understand why I wouldn't get any at all.