Female kickboxing....need some advice please!?

Hi, I'm considering joining a gym and training in kickboxing (competitive not aerobic). I am a very fit 22 year old female...my only concern is I am really tiny. I am about 4'11" and under 100lbs. I'm worried that I'll always be at a disadvantage for how small I am, especially if I do eventually compete in the ring. Should i worry about that? I have always been athletic, very fast, and have a competitive focused drive, but haven't really done much in the last few years. I want to do this for many reasons. Any advice or personal experience would be greatly appreciated! thanks!