Brown spotting getting more liquidy

Hey guys,

I am around 6 and 1/2 weeks. According to app 8 weeks. But from past scan. I am around 6 and half. I have been spotting for the past 2 weeks. It felt more liquidy today. But its still brown. My nurse says brown has nothing to worry. But am scared. I have an ultrasound tomorrow and she is like we must have a heartbeat tomorrow to confirm viability. I had a miscarriage last time, as no heart beat and i dint have any spotting last time. . Am scared

Can i please get some honest opinions, experiences and some prayers.

Update: in ultrasound they saw two yolksacs, one with a flickr of heart beat and the other with none. Over the next two days, my bleeding turned red and i passed off everything. I had an ultrasound today and there is nothing left in uterus.