Reassurance? And positive thoughts

So my periods are normally 4-5 days long and a pretty decent flow needing between regular and supers some days. But my last period I have very light pink and brown discharge when wiping and my “period” came 4 days late and I only bleed for 12-24 hours and it wasn’t even really enough for a pad. So I called my doctor thinking maybe this was it, maybe this is implantation. And they put an order in for me to get blood work. And went and got it done a few days later thinking it might be to early to tell even with blood work because I would have only been like 2 days along if anything, so j waiting for day 4 and went to get it done my results came back with hcg level less than 2.6. So I was thinking okay but it’s in my system I’m pregnant because the chemical hcg doesn’t just appear in your body and I was having few symptoms. But then mg doctor messaged me saying I’m not pregnant and to take a urine test in 2-3 weeks and if it’s positive to call and they will do more blood work and j asked if they could just do more blood work in 5 days and see if the levels rise at all, but they wouldn’t. I’m still having symptoms and still really think I am.