I think it should be fine as long as your dr isn't worried. Just make sure if you are having a tough time keeping food down, definitely make sure to keep up with your vitamins and water
I've lost 12 lbs in 3 weeks but I'm a little over weight so it's okay.
I am 11 weeks and lost 5kg so far
I've lost 7kg :( in 3weeks
I started out with a normal bmi btw
I've lost 8 pounds in not even 2 weeks
I lost 5 pounds this week due to morning nausea