So, apparently, she hasn't miscarried at all: naturally, we know this because of Max Clifford:
"After further examination it has been revealed that Kerry Katona is still pregnant. Kerry went back into hospital for a medical procedure last night. "However, a blood test revealed surprising results - her pregnancy hormones had gone up, not down."
Mind you, Clifford did also once insist to the papers that Katona "does not take drugs and never has. It's totally untrue, total lies."