Could I be?

For a few weeks I was real nauseous, I took three test all were negative well my pee is starting to burn and so far my AF is a day late, I even went to the hospital about a week and a half ago they didn't do anything but had me a pee in cup (bfn) could I be pregnant and was just too early to test or something else?? I don't even know what to do because the hospital didn't do anything and I feel helpless.