No Adsense Clicks for Six Days

I need opinions as to why for six days I've received no adsense clicks at all from the site in my signature.

I had in mind when I created the site a couiple of years ago that it would do okay with adsense, but even though I didn't expect this niche to make me rich, I've been very disappointed. At least, most days I do get Amazon sales. But I want adsense, too! The most I've ever made in adsense from this site has been around $5/week. I used to have sidebar ads, or a small banner at the top, and have tried different fonts sizes, trying to get a more successful click thru rate.

One thing I did differently with these ad units is that I slightly increased the padding so there is a tad more space between the ads and the content. Personally, I like this better...but maybe this is my problem?

The ad unit on the page in my signature has had 93 ad requests since Feb. 19 when I put in this particular ad unit on the home page and on the five other pages in the "bunions on feet overview" section, but no clicks. Between Feb 16 and 19, I had a different ad unit that is now only on the "bunion treatment overview" page. This larger ad unit with a different font has had 254 ad requests since Feb. 16, but no clicks.

Previously, I would occasionally go two days, maybe three, without a click, but after these new ad units and new layout, I've had the longest dry spell ever.

Any comments would be appreciated. Thanks so much.

Catherine