Low 19dpo beta

My beta today at 19 dpo was only 408. My dr said that’s within normal limits and I shouldn’t be concerned. She also put me on progesterone supplements because my progesterone was low also which she wasn’t concerned about either. Is 408 a reasonable number or should I prepare for the worst? I don’t have an ultrasound until 7 weeks.

EDIT: Yes another test is scheduled in two days