When braces are ‘tightened’, the teeth move only minimally, because there is very little space around them, and in the first few days patients notice a slight change in their position. After 14 days the cells responsible for moving the teeth through the bone have formed, and 2-3 weeks after the last check-up there is another noticeable movement of the teeth. Some discomfort is expected again at this point, which matches what patients describe. This is the normal cycle of tooth movement, and it takes 4-5 weeks.
This answer is for general information. Your own case needs an examination by an orthodontist.