Hcg levels

I got my first test on the 24th and my levels were 22 on the 26th I got them tested again they were at 108 so from what I understand they are going up every 20.91 hours. The doctor wants me to go back in at the end of next week to get them tested again. Should I be worried or does she want to keep a closer eye on me because I lost my angel in October.