Pagination through categories

Hi,

I’ve just started with WordPress and I imagine this is wonderfully easy answer to this question. At least I hope so.

I have a basic WP site and I am trying to use it as a full CMS.

I am using categories over pages and I have set up everything as I want it to look, except for one small thing.

I have set each category page to only show three posts so when you click on a category page you exclusively see the posts relating to that category. No problem.

But when you click for the next page all of the posts from the other categories are suddenly included, I want it so that when you paginate on the category lists that the list remains within the specific category, not all posts.

I’ve noticed that the initial category page uses ‘category.php’ and then when you click onto the next page you are taken to the ‘index.php’.
Is there any kind of else statement or post query I can use to solve this particular issue.

I hope this makes sense and thanks in advance.

Regards
MA