Ultrasound at 9 Weeks, Heartbeat 163. Is that okay?

Megan
I just had an ultrasound today, which is exactly 9 weeks. The tech told me the heart rate was 163. At 7 weeks the heart rate was 150. Do you think I need to be concerned that it isn't higher after 2 weeks time between appointments?
 
I'm hoping all is well. This is the third time I've been pregnant and I've never made it this far along successfully!