Need basic help: libraries and swf size

Hello

I use flash 8 just for simple animations (I’m not using AS yet, I need some time to learn).

I tried to do an animation with 10 jpg images (low resolution, 72 ppi). I imported all the images to the library. Then I created a graphic symbol from each one of them and drag them to stage. Each symbol is animated in a different layer.

The first time I used the images on stage I noticed they were larger than I needed them so I went to the library , right-clicked on the .jpg image and edited with Photoshop. The result was that my .swf was big and it became gigantic.

So, now I have smaller images and a bigger .swf. Why?
What can I do in the publish options to make it smaller?

Thank you, and sorry for being so basic with my questions

Joana