Give or take, how long do you wait to receive your coins? At what point do you start to become suspicious?
Which coin are you talking about? With ETH, it takes less than 60 seconds. On the other hand, for Bitcoin it can take anywhere from 30 minutes to 3 days, depending on the transaction fee used and the network load. Other currencies such as LTC, BCH, BSD and XLM comes somewhere in between these two.
My maximal waiting time was 2 weeks for bitcoin transaction in December, but at that point I was really nervous and uncomfortable. From that moment on I learned a valuable lesson of always estimating and applying reasonably high transaction fee.
With other coins, they normally don't get clogged and it is usually a matter of a few blocks. Exact confirmation time depends on their specific new-block-generation-time.