Do you usually have 啡色分泌 before your period? Because sometimes I get a little brown before my period.
I think if it's not your period, it could be early miscarriage. But some people have a little brown blood when they're pregnant too.
How's the blood right now? Maybe you can see for one or two more days. If it's red and getting more like a period, then you don't have to go to the doctor. But if it's just a little blood, you can test again and go to the doctor's.