4 week ultrasound??

I had a 4w ultrasound and the doctors said they didn’t see a sac and my betas were only 566. My cervix is still closed and they didn’t see anything in my ovaries or Fallopian tubes but there wasn’t a sac in my uterus.

Two days later my betas were 1431 but my next ultrasound isn’t until the 21st

With my son I didn’t have an ultrasound until 8weeks