green application pending but current status in trouble

[adeelsid]

Hi. My dad (US Citizen) applied for my green card last year. I am here in the US on an F1 visa. I just started my OPT. what if I am unable to get an H1. Do I need to leave the country or can I stick around because I have a pending green card application? I am 25years old so my green card application will take some time to process. Please advise.
Thanks in advance