going to start working out again

am afraid I am going to gain weight like I did last time or at least stop loosing weight. That is what happened before. I know that it was explained to me that it is just the muscles filling up with glycogin or something like that. And I would rather be slender and toned then skinny and flabby. So it is important. But keeping my fingers crossed and going to try to not let it discourage me. I got so used to getting on that scale and seeing it go down