Hi, first of all I hope you all had a lovely holiday 
DS is 12 weeks tomorrow and I'm switching him into a grobag after being swaddled in his cot for the first months of his life. I know I should've done it before because of the SIDS risk but he was sleeping so well in it! But I have to go back to work soon and a sleeping bag is a far more practical option and tbh I don't want to create work for myself when he's older, he seems fairly pliable to change atm... Or so I thought!
He slept fine for his daytime naps in it today, but he went down begrudgingly tonight and then woke at 6:50pm and didn't settle again until about 7:35. This is really unusual.
He normally has a quick feed/nappy change at about 10:30ish I guess, before we go to bed anyway and then sleeps through until 7:45. Oh God I'm in for a heller of a night aren't I? Any advice? How many nights should it take him to get used to it? How long should I persevere for?