No femur at 12 week scan?

I’m trying incredibly hard not to worry myself anymore, but I went for my 12 week scan today. After an abdominal scan, where the sonographer asked me to empty my bladder half way through, and then shake my hips to try and move baby, I then had a transvaginal scan where two sonographers had a good look at baby and concluded that there was one very visible fully formed leg and foot. However the second leg only has a tibia and foot present but no femur.

I’ve been referred to fetal medicine with an appointment next week, but I am absolutely freaking out. They sounded very definitive that there was an abnormality with the second leg and started talking about how this could be managed after birth.

Has anyone else had any similar experiences?