Thanks for your query.Based on the facts that you have posted it appears that you have undergone circumcision
3 weeks back and the wound has not healed up till now.
It appears that your Dr has taken secondary sutures 4 days ago and wound got infected.
Normally it takes 2-3 weeks to heal the wound completely,but it is delayed in your case due to infection.
Do not worry it will get healed up by doing dressing daily and use of antibiotics.