help please

ok so the nurse at my appointment today puts me at 6-8 weeks. this app will not let me update my last true period like the glow app will so the glow app has me at a little over 6 weeks and this app has me a little over 8 weeks. has anyone else had this issue? is there a solution I'm just not seeing? I'm getting very very frustrated with this.

update** all of this means I'm not getting the correct information. which means I have to dig for the correct information. which makes nurture useless to me as it stands right now. and yes. I know it's only two weeks off. I'm exhausted. I'm moody. and I dont like when things dont sync right on a normal basis...