what's 3 pages? A4 pages? A3?
For preview to display more pages in the drawer, it must be a mutiple page document - like a PDF for example.
Also, we can't say whether or not it's a problem with the program you created it in, since you didn't specify which program that was.
If you want it to print actual size, across 3 pages, then you'd need to tile the image. That means that the image is broken down into segments and printed on separate pages. I don't believe Preview can do this. Aside from apps such as Illustrator and Indesign, I don't know of any free ones that will do the job for you.
I tried a quick search then, but with no luck. I remember other members here recommending apps, so I'm sure someone will list something here pretty soon.
Your only other option is to scale the image down to fit your paper size, or take the image to a print place and have them do it.