Boy or too early to tell? - 13 weeks

Kelly • Registered Nurse ❤️. Married since 2015. Experienced 4 losses. Rainbow baby William Logan born on Mother's Day 2017 👶
This was taken at 13+1.  Is it definitely a boy or is it too early and just a nub?  I asked the tech and she didn't seem to know what I was talking about. She said it's a boy, but I thought 13 weeks was too early for a shot like this?