This is normal, however what often happens is the reverse situation, which is equally annoying.

1. You order something, and ask how long it will take.
2. Vendor sucks teeth, shakes head and says, "This is going to be a problem, it's going to take at least 9 weeks."
3. A week and a half later, the vendor rings up and proudly announces, "Your goods are here and ready to pick up!"

Has happened to me with ordering new bank cards, and particularly annoyingly, with the nursery furniture for our new baby. The goods had to wait in the shop (something the vendor was not happy about), as the baby's room was not ready, and we simply had not had time to save up for them.

Cheers

Jim