We would not suggest Physical exercise involving the knee joint till diagnosed properly.
Ask if your doctor can interpret an MRI or any Radiologist who can interpret an MRI. If so go for an MRI and get to know about your menisci and other ligaments condition properly before you undertake all these Physical exercises.
Do not come to diagnosis about menisci injuries, if you had meniscal tear then you present with symptoms of swollen tender knee and ask your doctor to do Mc Murray's and Apley's test on your knee to clinially know if you have meniscal injuries.
Unfortunately, living in Canada, it can take a very long time (months) to get in to see a specialist, which is why I already went to my family doctor who did all kinds of mobility tests and suggested physio therapy to start with. I just wanted to know, if in fact I do have a torn meniscus, would riding a stationery bike cause more damage? There is no pain at all when I exercised on it today. It seems the only pain I have is when I walk because I straighten my knee. when I use the bike my knee never straightens completely, perhaps that is why it does not hurt?
Before that go to an orthopaedician and subject yourself to examination. By your signs and symptoms the doctor would conclude if you have a problem with your ligaments inside the knee. They are very important for you, try to preserve them and when you are sure you did not damage anything, go for all forms of exercise.
In future remember always to wear proper footwear and walk on proper ground.