Normal hcg levels?

Kimberlee • 27 | Married | Two boys, & pregnant with baby #3! 🤞🏼❤️
Went in for a blood test to make sure I was pregnant (had taken three home pregnancy tests and all were positive) at 2w6d & my levels were at 28. Does that seem normal? Doctor wants me to go weekly to see if it's doubling like its supposed to.