I have an egg in my inventory without getting one from a stop. Is this a known bug?

So I hatched an egg and spun a couple stops before returning home without receiving another egg. Now that I'm home I checked my eggs and I have 9 somehow. The egg that I hatched was a 2km and that's the distance this new egg is as well. I even checked my journal thinking I may have just missed the egg but it doesn't say I received one since hatching the last egg either. Is this a known bug? Or could I be missing something here?