Is my 15 week old baby having a growth spurt?

Common times for growth spurts are during the first few days at home and around 7-10 days, 2-3 weeks, 4-6 weeks, 3 months, 4 months, 6 months and 9 months (more or less). Babies don't read calendars, however, so your baby may do things differently.Growth spurts don't stop after the first year - most moms notice growth spurts every few months during the toddler years and periodically thereafter on through the teenage years.