What to do if vomiting occurs at the beginning of taking birth control pills?

If you are not sure that the tablet has been absorbed due to vomiting (this risk occurs if vomiting occurs within 3-4 hours after taking the tablet), take another tablet as soon as possible. If you have taken an additional tablet within 12 hours of taking a tablet that you are not sure will be absorbed, protection against pregnancy is maintained and there is no need for an additional method of contraception. If you have not taken an "extra tablet" within 12 hours, take it even if it means taking a "double" dose the next day. In addition, a mechanical method of contraception should be used for 7 days, most often it is a condom. If there has been no intercourse within 7 days before taking 1 tablet, provided that the above recommendations are followed, there is no reason to worry about the risk of pregnancy. I encourage you to read the text: https://www.gdziepolek.pl/artykuly/jak-prawidlowo-stosowac-antykoncepcje

To @Ulka: Yes. It is necessary to regularly take tablets for 7 days. This is due to the mechanism of action of the drug: "Adequate inhibition of the hypothalamic-pituitary-ovarian axis requires uninterrupted intake of tablets for 7 days."

So in a situation in which, for example, for the first 2 weeks I would take tablets irregularly, for the next 7 days I have to use the tablets regularly to protect myself?

For @Ulka: Yes, the full contraceptive effect is achieved after 7 days of continuous use of contraceptive pills.

So in such a situation, when 1 tablet may not have absorbed, I should use the tablets regularly for 7 days so that the protection returns?

For @Ulka: You can have sex without additional protection from the 9th day of using the tablets from the current blister.

In such a situation, when can I have intercourse without protection?