Natural Cycles App and migraines

You have to take your temperature and do a ovulation test ( wee sample ) both in the morning then you add all in the app and it tells you if is a red day ( which you have to use another contraceptive method ) o green then you can have sex without contraception because when you have a green day you are not meant to get pregnant . I think if you want to get pregnant go for this app ! but as contraception is not very good as you hardly ever get green days and when you get them ( very rare ) you feel you can still getting pregnant also boyfriends / partners find so difficult to trust the app which it makes it even more difficult for the woman . As an app works very well and is interesting to know when do you ovulate or if you don't ovulate or if you ovulate twice but as contraception needs improvement