What do these symptoms mean?

Hi y’all! I’m 9DPO and af isn’t due for about 5 days. I have been having bad lower back pain for a few days now, got super nauseous yesterday and a little today, and now I’m laying down for bed and I have like a light pulling/ pressure on the left side of my uterus.

I took a test yesterday when I got nauseous and got a BFN. :(

I’m worried that it’s early signs of ectopic because it’s only on my left side but hopeful that it’s implantation... no bleeding though. Let me know what you think!! Thanks in advance :)