Our Android app does not support SD backups. If you remember doing a backup to your SD card in the past, you may have had a a different app called “My Period And Ovulation Tracker”. It looks very similar to ours, except it has a picture of a girl on the home screen. If you had this other app, you can restore from it’s backup by following the instructions in settings/data/restore from My Period and Ovulation Tracker. If this does not work, please create a backup account from our app and email support at gpapps.com your account email address and the backup file. We will upload your backup to your account so you can restore from it.