Adding your spouse to your Glow

I show my guy screen shots all the time of my calendar from Glow. I know there’s a way to add him and he can download the app and see for himself my cycle, ovulation, etc.

My question is... if I add him, can he see back past the date I add him or it starts when I add him? We’ve been together almost 7 months but before him I had a FWB that he isn’t fond of. I don’t want to cause problems bc I track the days I had sex. If he can go past the time I added him, he’ll see before with the other guy and be upset/jealous even tho he knows it’s ridiculous. (I get it, I have feelings too about anyone before me even if it’s dumb. And he’d never cause a fight over it, I just want to avoid it if possible.)

Can you tell me how it works before I start it with him?