Toddler started crying to sleep

[Nix99]

DS is nearly 21mo and for a long time now has put himself to sleep for naps and bedtime by just lying still and drifting off. The last week, however, he is now screaming and crying when we put him in his cot. He has just cut 2 canines and the other 2 are very close so I'm assuming it is this but he just seems so happy when he's not in bed. I guess I'm just worried if it's something else too and if this is how it's going to be from now on; with him crying before sleep. Weve been giving nurofen and anbesol before he goes in the cot. Anyone else had this and come out the other side?

DS2 is about this age and has always been good at settling himself to sleep, but did also have a little period recently of crying when we put him in the cot. We've found that putting some toys in there and letting him take a few books in sorted it out - when he's whingeing for another story, I let him just take it with him, and he bips around in the cot 'reading' it until he's ready to lie down and go to sleep.