You did not write how many days after the intercourse a blood test was performed. If it was performed at least 7 days after intercourse, the result can be considered reliable. The result obtained (beta-HCG concentration equal to 0.2 mIU/ml) indicates that there is no pregnancy.

Late menstruation does not necessarily mean pregnancy, it can be caused by, for example, stress, intense training, restrictive diet, fatigue, hormonal disorders. A one-time delay in menstruation should not be alarming, but if it does not occur in the coming days or you usually menstruate irregularly, it is worth considering consulting a gynecologist. The Gdziepolek.pl portal allows you to use teleconsultations if necessary:

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

I encourage you to read:

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