6 weeks 6 days, fetal pole but no yolk sac

So last week I went in at exactly 6 weeks and they saw the yolk sac but no baby. Now today at 6 weeks 6 days, they saw a fetal pole that measured 5 weeks 6 days but couldn't find the yolk sac this time. I go back on Tuesday to check again but she said that its most likely not a viable pregnancy and I'll be miscarring soon. 💔 Has this happened to anyone else?