why do some poeple say that having a wedding or giving birth in the month of safar is bad luck.

The people in the time of Jaahiliyyah (pre-Islamic era) used to regard the month of Safar as a bad luck month. Rasulullah [sallallaahu alayhi wasallam] removed this misconception and wrong belief and stated, ‘There is no (bad luck in the month of) Safar.’ (Bukhari)

As Muslims, our belief is all good and bad is from Allah. He knows the destiny of all. Bad omens is thus prohibited.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai