That during sleep training (CIO) there's a 4th day regression? We started on Tuesday and LO cried for an hour but has been semi sleeping through the night since then. I say semi because he would still wake up around 3/4 am but not cry but not fall straight back to sleep either. He would play/fuss for sometimes up to 2 hours before finally falling back to sleep! Today is day 4 and he woke up at 4 and started crying instead and I'm trying to ignore him :(. Is this a 4th day regression??