Just so you know, a puppy is never completely housetrained until they are 6 months old. For some breeds, even later. This means that though you may be making tremendous progress housetraining, there will be "mistakes". Sometimes for reasons you can't figure out! Don't fret about it. Stay focused on the progress you are making. Your confidence in the techniques you are using to house train your puppy will ensure your success.
Introduce your new pup to its new home, family and their role. Just like when you are new to a place or group, your new pet may be bursting with curiosity, excitement, fear or joy. Now is the best time to lay out the foundation for a good and pleasant relationship with your pet. For a puppy to settle in and learn to trust and respect you and everyone at home, it is very important to establish your expectations of your puppy and be consistent with them.