Bleeding and brown discharge????

Hey y'all! I am 6w3d and I have had bleeding 5 different times over the last week. Like a lot of blood and sharp pains/cramping. And when I'm not bleeding there is constant brown discharge. I called my doctor and went to Womens urgent care bc I just knew I was having a mc. they did an ultrasound and found baby and a heartbeat! They said they weren't sure what was going on but all I can do is just wait. Has anyone experienced anything like this? I know they say some bleeding can be normal but this just doesn't feel right.