45,000 quant HCG test

I'm wondering if any of you can shed some light on this information or have similar experiences. 
I'm supposed to be 7 weeks and 1 day along and had a 45,000 on the quant test. At this point they did schedule me an ultrasound for Aug 28 but am wondering about your experiences. Twins DO run in my family but I also could be farther along than I thought. I think I had a miscarriage in June and got pregnant right away in July so I'm not sure what a 45,000 quant means. I'm curious what you all are testing and at what stage? ie. how many weeks, and what HCG level, and multiples or not. Thanks Ladies!