I agree with bonj...doctors will just recommend pain killers, and you will have to wait several weeks for a physio through the NHS. I have at present got knee pain, and have had it for 3 months now. It's getting better now, but i think you might of pulled a ligament or two.
Best course of action is not to do any cycling, especially if you feel pain while doing it. Walking does no harm as long as you wear comfortable shoes (trainers). Take pills such as glucosmine with chondroitin and celadrin. I've been taking celadrin for about a week and the pain has reduced a lot. Not a 100% but i when i will be i will be back on that bike in a flash. Best thing to do is not to aggravate the knee(s) you'll do long term damage if you do.