Just started riding a bike. Only rode 3 times, but have been running 40+ miles per week.

Last ride, a few hours later, I could feel the tendon just above the back of my knee on the inside.

It doesnt hurt or ache, but when I walk, I can feel the the tendon. It is odd. When I run, it doesnt hurt, nor does it hurt after running.

Any ideas what this is? I have been dealing with it for a week. Took a week off the bike hoping it would go away, but it hasnt. Again, it doesnt hurt, I can just feel it engage when I walk and such.