Your levels seem good. You can always call your doc and request a ultrasound due to your history of an ectopic. That is what I did when I found out I was pregnant after my ectopic.
Ur levels seem pretty good ectopic pregnancy levels are normally much lower and dnt come close to doubling , i had a ectopic pregnancy last dec and my levels were nothing like that I had my first level at 158 then 10 days later it was only 519 but mine was only diagnosed by surgury , ultrasound and ct scan showed nothing , but if u are worried go get it checked but if u ask me it looks pretty good , good luck
Your hcg level seem to doubling okay. Have you gotteb another blood test? Only way to prove it won't be ectopic would be an ultrasound.