Sayang, please call your doctor or go to the hospital right away to check this out, yellowish discharge after C-section needs to be seen by medical staff, especially with the tenderness you're feeling. Don't wait on this one, okay? I know it's worrying, but better safe than sorry postpartum, a few of us mums have learned the hard way that anything unusual down there after surgery should get checked immediately. Your body's healing from a big operation, so don't second-guess the signals it's sending. Take care of yourself, and get that looked at today!