Question about cycling my tank?

i bought it almost 4 days ago and i didnt know u werent supposed to put fish in it the first day, so i did and then they died sadly, so i let the tank run til now, and for some reason the tank doesnt look like it has bacteria. cuz yesterday when my fish died there was bacteria and today there isnt. is that ok? because i did let the tank run. should i make it mor dirtier? or there is no need to? and if so how do i make it dirtier? i dont have fish in it anymore cuz i found out u werent suppose to by the way