Spotting at 8 weeks.

My appointment is a couple weeks away. I had small pink spotting yesterday. No cramps. No pain. Nothing. Saw the baby at an ultrasound place on Tuesday! Heart rate was 165. She said there was a small spot of implantation blood she could see on the ultrasound. Then I had a tiny bit of blood today. Darker. But like the size of a quarter. Again, no cramping still lots of symptoms of pregnancy. Should I be worried? Is this normal?