iPad order running late

Hello, I recently ordered an iPad on June 30th, about 3 weeks ago. It was said to arrive between July 16 and July 23rd. However, today is the 20th and the order just barely switched to "preparing to ship." I will not be present at home starting from the 29th, and I'm afraid that the order may come late and I will miss the package. Should I be concerned about this, or is this considered a regular thing?