Hello everyone. My Sky is a Blue Chihuahua. She weighs about 3.25-3.5 pounds and is very active. She sleeps next to me and I see her immediately when we both wake up. When she wakes up she immediately stretches about 3-4 times first bowing and then extending her back legs. When she does this I hear like 3 or 4 popping noises like I sometimes have after laying around for a long time. The thing is, I've never heard this come from a dog before. Is this normal or should I be worried?