More accurate due date?

I know I won't know a more accurate due date until I meet with my doctor (in the works of getting that set up soon). But, I've played around with a few pregnancy trackers and have gotten ranges of being from 5w 3d on Glow all the way to 7 weeks on a couple other trackers. I feel like Glow is giving me a more accurate estimate since its been tracking my periods since April or May. Has anyone else had this issue until they meet with their OB?  Which was more accurate?