So if you're 5 weeks and some days, you're actually in the 6th week of your pregnancy.
Just like if you're 25 years old, you're in the 26th year of your life, and your 26th birthday is when you've completed your 26th year. Does that make sense?
I would say read about the baby at 5 weeks, and just know that when you're 5w6d, it's almost to the 6 weeks stage. It's not like your baby goes from appleseed to sweet pea instantly when the clock turns midnight.
5 weeks 6 days means you have completed 5 weeks and an additional 6 days. It's a little confusing- you're technically in your sixth week. Your week number is the week you just finished. Hope that makes sense!
PP explained it well so I'll just add that most pregnancy apps give you the choice to be set so you view either the week you're "in" or the week you've "completed".
Re: CONFUSED!?!