Miscarriages

I've had 3 miscarriags, 3/6 pregnancies. I have a 5 year old daughter now and am almost 7 weeks pregnant. In the summer I miscarried at 6 weeks. I started spotting then at 5, found out my levels were low and saw nothing on ultrasound, and before I could do anything further I miscarried. I've made it past that point but started spotting 2 days ago and cramps, similar to the first time, but I seem to be ok if I rest. I can't get a doctor's appt until Monday and I'm wondering what to do to make it to then and wondering what can be done to prevent another miscarriage.