8 weeks and spotting

So I’ve had 3 previous miscarriages, I found out I was pregnant on july 11th, according to my last period, I’m supposed to be 8w2d. I started spotting and cramping last night, I went ahead and called my ob and they got me right in for a ultrasound. My baby looked great, I am measuring right on track and the heart rate was 166❤️❤️