Third trimester?

LeahπŸ€°πŸΌπŸ‘ΆπŸΌπŸ’– β€’ πŸ‡¬πŸ‡§. due my first little girl in September 2019 πŸ’– two gorgeous step children πŸ’šπŸ’™

When is the 3rd trimester? 27 weeks or 28 weeks?