Why does there be sagging bleeding when using the tablets?

You have not written what pills you are talking about. Aidee contraceptive pills are tagged with the question. As for this preparation - please read on. During their use, there should be bleeding, which may be different from the "ordinary" menstruation - scanty or just strong and abundant. Such changes in the bleeding profile are treated as a type of side effect of the drug: https://www.gdziepolek.pl/artykuly/jak-i-dlaczego-zglaszac-dzialania-niepozadane So-called bleeding or mid-cycle spotting may occur at the beginning of contraception (usually during the first three months). After this time, they should be consulted with a doctor. Since the entry does not contain any additional information, it is unfortunately difficult to answer in more detail. Rapid and very heavy bleeding, or "hemorrhagic menstruation" should prompt you to contact a gynecologist. I enclose additional information: https://www.gdziepolek.pl/artykuly/jak-i-dlaczego-zglaszac-dzialania-niepozadane