Ovulation day change?

Cheyenne • Momma of two angel babies 2/1/18 👼🏻 2/3/19 & a sweet girl 12/15/19 👶🏼

So my ovulation date on here was incorrect (one day late on the app) and now it’s moved back another day. Is there a way to fix this? I don’t have the premium app, if that makes a difference. I only have the free one