I was on F1 since August, 2008 till September, 2011. After I'm on H1 now.

I never file IRS 8843 form when I was a student. Is it possible to file now. Will that hurt me in the future?

You can still file the forms.
Send each year separately.
There is no penalty for filing form 8843 late.

Thanks for your reply but where can I get the forms for previous years. On IRS website I can see only 2011 tax forms.