Spotting 7 weeks...

I went the hospital on the 7th because I started spotting and it looked like my last miscarriage. My ultrasound measured 6w5d and a heartbeat of 129. My levels that night were 10,686.0 and the doctor said everything was great. No pelvic exam though. They didn't know why I was spotting. I received my RhoGam shot and sent on my way after 5 hours in the room. It had pretty much stopped by the time I left. Now I am spotting again. It almost looked like old blood? Dark brown. Still there. Can't get a hold of my doctor until tomorrow. I'm trying to stay stress free and not worry but I am freakin out! Does anyone have any advice?