Painful stretching?

Chelsea • LRK 5.30.16💖 MGK 7.5.19💙

I’m 18 weeks and this is my second pregnancy. Recently I’ve been getting this weird sensation across my belly whenever I lean or reach down while sitting/laying down. It feels like my abdominal muscles are stretching flat like a ruler. It feels like a giant kick but I know it’s not. Just wondering if anyone else has experienced this? It doesn’t hurt but it’s definitely uncomfortable