Need opinions

Vanessa • 21. 1 baby, due with #2 02/07/20. Married

So ladies.. today I went for my first ultrasound.. I’m supposed to be 8 weeks.. but the sac is measuring at 5 weeks 2 days.. the OB kept telling me that my baby probably stopped growing.😔💔 has anyone on here experienced this or knows what’s going on?