Welcome to the forum.
If you can feel a slight pop or crack in the area on bending then an injury
of the internal structures of the knee is likely.
You can help the improvement by-
1. Avoid any strenuous knee exercises, lifting weights, climbing stairs, cycling, etc.
2. Take a mild pain killer like acetaminophen
every 8 hourly.
3. Do a hot fomentation in the area twice daily.
4. You can apply a local analgesic
gel like Volini
5. Use an elastic knee brace
for better knee support while walking.
Do consult an Orthopedician for a physical examination and stronger prescription medicines in case there is swelling, persistent pain and difficulty in walking.
I hope this is helpful to you.