Hcg level 1,600?

K
Hi ladies I had my first blood draw and it came back at 73 and then 48 hours later it went to 281 and 6 days later it is now at 1,600. Is this a normal number for me within the 6 days? I am also almost 6 weeks pregnant and have light spotting. Yesterday I had an ultrasound and it showed a small sac with the yolk inside.