Baby didn't really gain weight

Jenna • 🎀Addison Leigh 9/9/17 | Mia Jane 4/23/19🎀

Hey all. So I'm 36+6 today and went for my weekly checkup. Nst looked great but during the sono the baby's head was very low in my pelvis and she was moving like crazy so it was hard to measure her. With what they got it looks like she didn't gain any weight this last week. I know these are just estimates and no one was worried, but of course I got nervous. Anyone experience this?