Implantation or aunty Flo-ho

I'm currently 9dpo today. Maybe 8apo, it was a weird cycle. My OB asked me to take a blood panel around this time so yesterday I went for it.

HCG levels returned <2.0, negative.

This morning I had brown discharge, a little in my undie but more so when I wiped. Was it too early to do labs? I'm abt 8-9 dpo today. When do labs and urine sticks pick up HCG?