Post Office Hold Question?

Okay, so I recently moved and I put my mail on hold at my local post office. I went out of state for about two and a half weeks, and when I came back to get the mail on hold, there was no mail there! The mail I was expecting was sensitive and incredibly important. I was expecting mail from multiple sources as well, and I know when the mail was sent, so I'm sure it should be there. The obvious thing to do would be to check my old mailbox, but the address I moved from was an apartment, and the manager will not allow me to check the mailbox (It requires a key). Can I have a post office employee grab all the mail addressed to me the next time they drop off mail there? Any tips or suggestions would be greatly appreciated.