Early pregnancy

Im a first time mum after a molar pregnancy in November 2020, and im just wondering if its possible to be earlier than the app says...my last period was 1/1/2021 and i finished 6/1/2021, i found out i was pregnant 30/1/2021 and so the nurture app puts me at 4 weeks 6 days but the glow app puts-me at 5 weeks exactly today (4/2/2021) with a due date of 8/10/2021...i am asking because i took a test mid january and it said negative and i have no idea how this stuff works tbh with the tests and how its worked out. Im just hoping for a healthy pregnancy after all this is my rainbow baby.