Sayang, please go see your doctor or go to the hospital now , darah merah dengan gumpal on day 28 tu tidak normal, especially dengan sakit pada luka caesar. Even kalau luar nampak kering, kena check dalam properly. A few of us mums went through this and lepas jumpa doctor, alhamdulillah semuanya okay, but it's better to be safe. Don't wait lagi, ya. Your doctor needs to check if everything's healing properly inside. Take care!