definitaly go to a ortho and have the knee checked out!! besides having a bike fit done.

I had very similar pain to what you are describing!!! and I ended up needing knee surgery(mri showed the issue), but I was lucky and was back on the bike within a week of the surgery(but it took me almost 2 months to get it looked at, so I was off the bike off and on for those months).

Just have your bike fitted! make sure your saddle and peddle(ahhh spelling is not looking right but i am having a brain fart) positions are correct, even being off a mm can make a huge difference!