Edit/Delete calendar??

Julia • Married and just starting ttc! Trusting in the One who makes all things possible! ⚓️❤️
When I signed up I input my info, I just started af on the 3rd. I saved it and when I went back in it had moved my period range to the 7th and 8th. I deleted my old account and started new to try and fix this problem I had before. Why does it not let me edit/delete? I love this app but can't use it if it's going to keep doing this.