Calming signals are also used by confident dogs to put less-confident dogs at ease. So when a confident dog meets a submissive dog, the confident dog may display calming signals like yawning, or ground sniffing to show the other dog that he is not a treat, and to communicate peaceful intentions.
That is what your dog is doing. It's not that he is unsure, it is that he want you to know for sure that his actions are in no way a challenge to your position. Looking over top of you, having his face close to yours, could be dominant positions, and just so you know that he is just playing and being friendly and affectionate, he is throwing in all those calming signals for you - so you don't mis-judge his intentions.
BH, OB1, TR1, AD
Rottweiler/Hairy Dog mix?? Shelter rescue
Gryffon Vom Wildhaus