This is probably a stupid question. I use mint.com to track my expenses. I noticed a $7.50 charge from Delta to my non-DL Amex card. That same day I had a ticket that I bought the prior day reissued so an eCert could be applied. But I bought that ticket with my DL Amex card. I could not figure out where that $7.50 came from and I couldn't find any place on delta.com which shows an order history (what you bought, when you bought it and how much you paid).

Finally, I looked on the amex website, saw that the charge was attached to a ticket number and realized that it was from an award ticket I bought the same day (oops). Still, there must be some place on delta.com with an order history, right?