How to strengthen core 19w post C-Sec

I am doing the 30 day plank challenge, and very sore this morning. Google it and print it or get the free app on a smart phone

The most challenging core exercises I've ever done are kegel progressions. I started by doing a mini crunch, activating my pelvic floor and transverse abdominals simultaneously. It's like a pelvic tilt, and you'll feel a tightening of your lower abdomen especially. I progressed to doing single leg glute bridges, lowering and raising the elevated leg. Keeping the abs and pelvic floor engaged, and doing the exercise slowly, focusing on keeping the torso stable. Eventually adding in a leg raise progression, making sure I still engage the pelvic floor every time and do the exercise slowly.