After the change from Elin to Atywia Daily, is protection provided immediately?

Good morning, recently the doctor changed my Elin tablets to Atywia daily. I was to start the new tablets after the end of the Elin blister and after the bleeding (after a 7-day break), which is as if I was starting another pack of Elin. However, I do not know whether contraceptive protection is provided from 1 tablet of a new drug or only after some time and you have to use other methods of contraception. There was nothing mentioned in the prescription. Best regards