ANSWER:

You are sinful for praying is such short clothes knowing that your awrah might be exposed.

If you are not certain that it was revealed, you don’t need to repeat the prayers. 

There’s a possibility that a part of my backside mught have been exposed in ruku and sujood due to the clothe being short. However I don’t know for sure and this was not in my mind that my clothes were short. Now that I doubt it, do I repeat my prayers that I have doubts about? Same goes about my hair too which might have been exposed but I’m not sure. I’m a woman