Thank you all of your for your great suggestions. My major doesn't qualify for STEM extension. My hospital told that it doesn't fall under non-profits. My employer had already filed for h1b but the quota for h1b for this year has all gone. Therefore, he said he will have to file for h1b for me again as soon as the filing opens again which will be April 1st. but my OPT date ends on Febraruary. Will I be able to stay in US legally from the point my OPT expires until my h1b gets approved on August?