That's too long
It does down in 48-72 hours.
If it's elevated after 3 weeks, there is on-going injury or you have a rare variant called "macro cpk" in which it is always elevated but normal (ie, not indicative of injury). The pattern and level are important. Slight elevations have no clinical significance. CPK iso-enzymes can help determine the source. Your doctor is the best one to make this evaluation.