Hi Neck cracking is not good habit, you are already getting mild pain, pain associated with crackling needs to evaluated , consult orthopedic surgeon

hi, cracking your neck may not be the cause of your neck pain.. was there any incident that strained your neck recently(long journey, uncomfortable sleeping/sitting posture, falls, sports injury).. try local hot fomentation/ cold fomentation... some gentle neck exercises, if not relieved please meet your local orthopedist for further evaluation

All people tend to crack their neck at times It becomes a problem when it is repeatedly done and becomes a habit. You can end up having a stiff neck if you don't avoid this . I would suggest you stop the habit immediately. Try doing some isometric neck exercises everyone you want to crack your neck