Scared I'm going to lose my rainbow

According to my LMP I'm 6w2d and last night I started spotting.. but this morning it got a little heavier. It's been brown and watery the whole time. No cramping.. just feeling "achy" like AF is coming. I had a MMC in May at 12w4d so of course I'm paranoid and worry about everything this time around. I went to the ER just for a peace of mind. They did blood work and my HCG was fine. So they did an ultrasound I seen baby which is measuring 6w0d and the heart beat was running 115-120. My cervix were closed and everything looked okay except for a large cyst on one of my ovaries. The ER doctor said he wasn't concerned since baby looked okay.. he said everything could be stretching and maybe irritated since I did miscarry in May and I'm not having bright red blood. He gave me paperwork on a "threatened miscarriage" but he said he doesn't think that will happen and told me not to have sex, exercise and get rest till I follow up with my OB. I have an appointment with my OB on the 31st at 830am. I'm still worried because I'm still spotting when I wipe. Has anyone ever experienced this and had a good outcome?