Slow growth

April 9th I was 5w2d according to ultrasound and the gestational sac was 6mm. It’s suppose to grow 1mm each day. I had my second ultrasound done April 22 and should of been 7w1d but they measured it at 6w.. the gestational sac was now 11mm and it should of been 19mm. Dr said it probably stopped growing April 14th. Has this happened to anyone early in pregnancy? What was your outcome?