I haven’t felt her move!

Ol

I haven’t felt my baby girl move at all today! I’m super worried. I felt a pop/crack in my back yesterday and she hasn’t moved since. I’m really worried and feel like I should go to the ER to make sure she’s okay but I know they will say it’s a threatened miscarriage. I’m 18 weeks and 3 days she very active through out the day and even more at night but last night and today she just... nothing!