My 18 month old son recently began a pattern of waking up repeatedly between 3 and 6 am. He cries and latches on but will unlatch after a minute and roll over like he's going to sleep. Then he will wake up again a few minutes later and repeat the process. He does this until 6 am when he finally rolls over and sleeps till 8am. I don't know what is causing this or what to do. He nurses when he goes to sleep around 8pm and again at 11pm. This is unusual behavior for him and I'm afraid I'm missing something. Not to mention it is killing me to lose this much sleep every morning. Any advice?