Brown spotting

So I went to the doctor yesterday from my last menstral I should be 9 weeks along but the baby measured 6 weeks heart rate was faster then it was before, kidneys are working, sac looks good, this morning I peed wiped and saw some brown spotting, wiped again still there. Peed about 15 mins later no spotting.. im freaking out.. shd I b scared? Dr is sending me for blood work to check hcg n progesterone levels again.. what is this spotting ?