Our DS2 is 2.5 years old and for past 6 weeks keeps waking up once a night for a drink. We've left cups of water by his bed, on the stairs (which has the landing light on) but still comes up to our bedroom. It seems to be a habit now. He's not great at going to bed unless he's worn out with no daytime sleep but in the past once he's asleep he doesn't wake up unless he's ill. I'm 6 months pregnant so v.tired and need unbroken sleep. Any suggestions