So can you have unprotected sex all the time with your spouse while taking birth control pill the same time every day ?

Basics=yes: The pill when taken as prescribed will prevent egg release during every cycle.No egg=no pregnancy. Missing pills may allow egg release.

You can....: .... but if you are asking if taking birth control pills will guarantee you will not get pregnant, the answer is no. Taken correctly, it is up to 99.9% effective. The only 100% guaranteed way is abstinence.