My DS is 18 months. He's always been a lovely, relaxed and very cheerful little lad. Full of smiles, and really easy going. He's PFB btw. 
Over the last few days he's been whinging loads, just grumpy really and more clingy than usual. He wakes up and cries immediately, usually he'd 'chat' to wake me. He seems to get frustrated easily and cries/moans as a result. He's also been refusing his naps. He might be teething, but it's never bothered him badly before.
I think I'm overthinking this because he's starting nursery next week and I'm already nervous about that, but any ideas / experiences of similar would be gratefully received.