So confused.

On my Home Screen of this app says I’m 4 weeks pregnant. And it just popped up “congrats your five weeks pregnant” and if I click the calendar on here it says 5 . Can someone help me out ? My period is due Jan 29 (today) but I had a blood test on Monday and it was confirmed I was pregnant with my number being 103.75. The app is confusing me giving me two different numbers 🤪