Pregnant?

Good afternoon ladies i have a question.

Could i be pregnancy symptoms at 4 dpo? Woke up this morning hubby and I were having sex when he noticed a bit of blood on the tip. I took a pregnancy test and it was negative l, i have been having nausea, headaches, and feeling dizzy since the morning accordong to me chart it estimates I'm 4 dpo this is my 1st time actually charting bbt daily. What do you guys think of this? Thanks in Advance 💓 Baby Dust to all 🙏