choosing profile pic

Hello,
I added a few pics. onto my profile and it told me they were waiting to be approved. When I click on My Account and Edit photos, it says my account it locked right now while the pics. be appoved. However, it randomly chose one and put it as my profile pic. How do I pick a different onw I had put on to be my profile pic? It was like it just picked one for me and I don't know how to pick a different one. I looked on here for a thread already about this, but one was hard to find, so I thought I would just ask :) Thanks!