Does the 3rd Trimester begin at week 28th or 29th everybody say different so now I am officially confused?

some charts go to 42weeks but most of the trimester charts I've looked @ on Google go to 40weeks so I just go by the 40week chart @djsmommy0516

O ok thanks @babychloe

im not sure but most of them say 27 whenever i look it up

@babychloe,

Is that chart accurate?

27