Stress (especially if it is severe) can significantly delay the onset of menstruation, as can intense physical exercise, excessive weight loss, and thyroid disease. The use of certain medications can also affect the menstrual cycle, but I don't think that any of the throat medications used could affect it. You have not mentioned what drugs you are specifically using, but among the drugs that can interfere with the time of menstrual bleeding are, among others, antidepressants, hypnotics, antihypertensives, glucocorticoids, antibiotics.

Since you have ruled out pregnancy, it is most likely that stress is the reason for the delay in your period. Menstruation should occur on days, depending on how you feel and the persistence of stress. If this is not the first situation of this type and menstruation does not occur in days, I encourage you to consult a doctor. You can make an appointment for a teleconsultation, e.g. through Gdziepolek:

https://www.gdziepolek.pl/telekonsultacja/z-ginekologiem

I recommend the article:

https://www.gdziepolek.pl/kategorie/leki-na-zaburzenia-miesiaczkowania