Went for my scheduled run today. Warm up was fine but as soon as I increased pace to my normal slow jog ouch! A twinge behind my left knee cap. I tried to run on for a bit but as I increased pace again it twinged. I didn't carry on running but did a brisk 4k walk instead with no more twinges.
Any advice? I have not had this before. No swelling but just a little tenderness behind my knee cap. I have iced it and taken some ibuprofen.