Try this:
<a href="http://www.fertilityfriend.com/home/1880f0%5bIMG%5dhttp://www.fertilityfriend.com/ticker/1880f0%5b/IMG%5d" target="_blank">
http://www.fertilityfriend.com/home/1880f0[IMG]http://www.fertilityfriend.com/ticker/1880f0
[/IMG]://http://www.fertilityfriend.com/home...r/1880f0
[/IMG]://http://www.fertilityfriend.com/home...r/1880f0
[/IMG]</a>
Copy and paste that into your signature and it should make your FF ticker be the link to your chart.
If you want a different graphic then pick the one you want, save it to your computer, then upoad it to a photo hosting site like
www.photobucket.com (its free) Once it is uploaded it will give you an IMG tag. Copy and paste that tag in between the [IMG] tags above, replacing the one for your ticker.
Hope that helps!