I recommend keeping his routine too. Although our 3yo DS wasn't in daycare, he found it very overwhelming to have his daddy home as well as having a new baby in the house. Having DH home was actually disruptive to him because DH didn't follow our normal routine and there were lots of tanties going on. When DH went back to work I found our DS calmed down too. I guess children find security in routine so it is probably best not to throw too many changes at them at once IYKWIM.

Best of luck with your new baby!