Ready to cry

Hi I'm on cycle day 44 and 21 dpo now. I just wish I knew what my body was doing. This is what is throwing me I had a brief moment of really light pink spotting bout a week after  unprotected sex.  I have had nothing since.  Seems like whenever I eat u can never get full.  Or when i do I want to throw it back up. I've already taken a couple of test of the was a bfn. 😥.  So I don't understand what my body is doing.  Talked to my ob they said wait until next month n they will do a test either urine or blood. But I'm scared that if they do it's gonna come back negative as well and if it does idk Wat to do.