With major US sports (NLF/NCAA Football, MLB, NBA/NCAA Basketball and NHL) this is almost always the case and usually, you should not have to wait more than one to two minutes for your bets to be graded.
With other sports such as Soccer, Tennis, Boxing and Golf, grading can take up to 10-15 minutes. In some cases it may take over 15 minutes; normally this only occurs with sports that receive less action from bettors, for example, darts or cycling.