Please Help- Body Problem?

I have a strange problem. During the day, I sweat under my arms a little. There aren't any HUGE stains, but there are some darker spots that suggest sweat. And because I sweat, I have some other problems. I don't know if it's the sweat or what, but I tend to smell a little too. Some days are worse than others. And yes, I use deodorant. Is this a normal problem? Any help would be greatly appreciated! If this helps, I am a 14-year-old girl. The problem started a little less than a year ago.

Also, negative comments will prove how immature you are and that you care about my question so much you wanted to answer it. I'm touched.