Measuring a week behind after previous ultrasound

E ❤ • 19| Mommy of Milanirose ❤️| expecting baby #2 May, 28th! 💙

2 weeks ago I had an ultrasound and baby measured 6w6d. Today baby measured only 7w4d. I was supposed to be 8w2d. Has this happened to any other mamas? I’m nervous and I’m not sure what to expect. Baby still had a heartbeat