Charged Twice for Shipping?

I ordered a set of EarPods on September 28th. I just checked my bank account today, and I think I was charged twice for shipping, listed under 2 separate transactions. My order total was $34.98. Shipping was $4.00, and tax was $1.98. That charge for $34.98 shows up on my bank statement on 9/28, and I have a hold also for 9/28 for $4.24. Before I contact apple, is this how they usually handle shipping costs? Seems strange for it to show up twice. Note that I haven't bought anything else, apps included, to explain the $4.24 charge.