Nub? Skull? 🤷🏼‍♀️ any theory at this point LOL

Monai • Married April 2018 💍 Baby girl born April 2019 💕 Baby 2 on the Way - 9/2021!

17w6d! Here is today’s scan. Only mom knows the gender until our reveal party Saturday. All I know is baby is measuring right on time, all checks out perfect, heart was 157 and weighs 7 ounces! Do you think boy or girl?!