If there is no bleeding two hours after taking the morning-after tablet, do I have to take another one?

As I understand you, you mean a preparation used after intercourse, which is to prevent unwanted pregnancy. Such a "morning-after" pill is not used to cause bleeding, so there is no need to take another one. There are currently two preparations used in emergency contraception on the market - their mechanism of action is to inhibit or shift ovulation. They do not interrupt an already existing pregnancy, do not act abortifacients and - as I mentioned - their mechanism of action is not to induce menstruation. I enclose information about contraception after intercourse that may be of interest to you: https://www.gdziepolek.pl/artykuly/tabletka-po-czyli-antykoncepcja-awaryjna https://www.gdziepolek.pl/kategorie/tabletka-po