Cycle Day 50, bfn

Looking for hope! 
Day 50 of what is normally a 33 day cycle. Have been having boughts of nausea since Saturday, but all in all, I don't feel any other symptoms. I have a doctors appointment but not for 2 more weeks. I'm done testing for a while, but just wondering if others have had the same situation that come out postive. Is it okay to have low enough hcg levels at this point IF I actually am pregnant?