When you press preview, you will have to press 'I'am not a robot' to ask/answer the question, but I thought I'm was the right spelling....
People frequently compain about this trivial typo.....you are not the first ....let it go. Maybe someday it will be fixed.
I worry more about the language and syntax skills of people asking questions.....really poor. Their errors are FAR more egregious than the " I'am vs I'm" in the CAPTCHA.