Seperation anxiety? Growth spurt?

My son has never been one to get fussy before bed. When he's tired, he goes to sleep without much fight. The past 2 nights he'll whine for a good 10 mins, toss/turn and the only way I can get him to sleep is by rocking him (something i havent done in months).. Once i put him down after falling asleep he's completely okay. He's just over a year and it's his 2nd week in daycare, so i was thinking maybe it was that but last week was tougher for him and he wasn't like this. He has no fever, his belly is soft (no gas/constipation) I don't know.. it's just so not like him.. Anyone else experience anything like this with their l.o's around this age group? TIA🙂