Well! That's the good thing about it; you can just call in on your PokeGear and request the egg, and when you get to the next town, it'll be be at the Pokemon Center waiting for you. And Cherrygrove is about... a three-day journey, so if you do it now, it'll definitely be there by the time you arrive.

[She grins; clearly, she just did it herself, and she's petting her Dratini, already reminiscing a little on the day she got his egg in Cherrgrove.]

The system they have for transporting Pokemon is pretty convenient. Oh, and keep in mind that some Pokemon take a lot longer to hatch than others. My Dratini took about three weeks, but Togepi [She pauses to point the 'gear at the little cutie by Houndour's feet.] only took a couple of days.