Bald Spot from Bleaching My Hair?

(female)
I usually color my hair and a few weeks ago i did a triple process where i had 3 different colors put in but the process of bleaching. My new roots started growing back so i decided to lighten them. While applying the bleach we noticed a bald spot at the back of my head. It was smooth soft and the same color of my scalp. It has feeling and it does not pain at all. Could the chemical have caused it!? Would it grow back? I am very worried

You should be worried. Bleach can burn the hair root and cause permanent balding. Wait it out for 3-6 months and you will know if it will reverse. Be careful in using too much or too strong bleaches. You can read more about this in my book, Hair Loss and Replacement for Dummies, where this is discussed in considerable detail.