2 weeks behind on ultrasound

Hello ladies. I have been having issues with my pregnancy and I was wondering if any of you had dealt with the same. I know the exact date of my last period, but during my first and second ultrasound I have measured two weeks behind in growth. I was also told I have a bicornuate uterus so I don't know if that has anything to do with it. Could any b of you ladies help ease my mind? 😔