Confused about gestational age

Br

Ok, I always think I’ve got this figured out and then I don’t. Maybe someone else can help me.

This app says today (May 29) I am 5 weeks.

Another app says today I am 5 weeks and 7 days.

Another app says I’m 4 weeks and 7 days.

My last period was April 25.

What the heck! Brain is melting.