Can I carry the flu without showing any symptoms?

Yes, most viruses can be in a human without showing symptoms. I don't know why that is so, but it's true. And incubation periods for flu doesn't last for more than 10 days. It rarely gets to 10 days anyway. You can carry the flu, yes, without showing any symptoms, and of course, you actually do have it, but your immune system is most likely fighting it off well.