You can do this exercise pregnant or not, but as you see below, I demonstrated it while pregnant with my second! This is a full body exercise, however you will feel the intensity in the abs and lower back.
Get on all 4’s on the ground. Lift your knees up (or keep them to the floor to modify). Tap the left shoulder with the right hand then put the right hand on the ground. Then take your left hand and tap your right shoulder. Repeat. Try to minimize movement in the whole body while tapping. Yes, you will move side to side a bit, but try to control and keep centered, with your hips facing the ground. Keep tension away from your head and neck and breathe!
Do 2-3 sets of 8-10 taps!
CHALLENGE: Do a set of push-ups in between each set of shoulder taps!