What Causes Pain On Inner Side Of Knee?

hello im a 56 year old male I have been getting pain since 14 December almost certain its medial ligament pain on inner side of right knee I have iced twice a day and pain is just about gone however afer walking all day working it starts to give me dull pain I am a competitive cyclist training 6 days a week weird thing is cycling does not bother me no pain until I use heavy gears should I rest or wats your advice