Miscarriage?!

Okay ladies. I’ve had two healthy pregnancies. I’ve remarried a year ago and I’ve recently had a miscarriage back in July. I found out I am pregnant again back in August.. but ever since I’ve had light red bleeding, not real heavy but not just a tad. My doctor said it was ok until i was hurting witch i wasn’t at the time but every once in a while I’ll get a light cramp then go away. Today the blood has turned brown. No cramping. I’m just wondering if anyone has had these symptoms and carried out a healthy pregnancy? I go have my ultrasound done Friday I had one last Friday and they ween a yok sack, and a little flicker(whatever that means) but no heartbeat yet. I’m a little over 7 weeks.