Uterine flutters

Samantha • I`m 26, married and have 3 kids, 8 months, 3 years and 6 years old. The husband and I are expecting #4 :)
I got my Mirena IUD out on 12-18 but I'm still getting those weird uterine flutters. Almost feels like a baby moving but even if I am pregnant there's no way I would feel it yet lol. Anyone else get this?