Spotting

A little nervous/scared. Today was a pretty hectic day. Was on my feet stretching and bending. Moving products around doing an inventory count. When I came home I noticed brown spotting. Nothing excessive but this is the first time I have had spotting.

I am exactly 6 weeks pregnant. My hcg last week was in the 900s and yesterday I was at 19137.

Since this was IVF I am already on progesterone and had been taking estrogen until the 3rd

Does this sound normal?