Brown Discharge while pregnant?

Bree

So im 15 weeks pregnant today. Well last weekend, on Sunday, i suddenly had a lot of bleeding. Dripping into the toilet and everything. I didn't soak a pad in a hour though. After a couple of hours it kinda looks went sporadic and even stopped for a while but came back lighter and would stop again etc. Well the following Tuesday(this past tuesday) i went to my regular appointment, that i already had scheduled, expecting to confirm miscarriage and discuss evacuation. The doctor said my cervix was closed and that she didn't see a active bleed and it looked like old blood. And to my surprise the baby is okay. Strong heart beat and growth is good. Im on strict bed rest now for two weeks but im still having brown discharge. its light. But im still worried about losing the baby. Any advice? Experiences? Im so scared.