First Dr appointment is Thursday!

So I'm going to be a mom for the first time. According to the info I initially entered into the app, my last cycle being Feb 1, Glow has my due date listed as Nov 8. But I could actually be further along than the 5 weeks I'm told! I'll find out for sure Thursday, but if there is a difference, how do I change the info in the app to reflect the actual due date? I want the information I'm getting to be accurate, at any rate. Any ideas?