It can be tricky to see your ads while they are working. We would strongly advise against looking for them while they are live, for fear that it will disrupt your impression data. Your ads rotate evenly in the ad network with other advertisers who have same or similar targeting.
The best way to see how your ads will look or appear is through the preview tools per platforms provided in Basecamp before the campaign goes live. Ask a member of the team if you cannot find these or if they have expired.