Originally Posted by CheshireCat
Go to the doctor. Better still get a referral to a rheumatologist.
Personal experience is that rheumatologists do not want to deal with osteoarthritis. Once blood work and imaging comes back not showing anything significant they'll happily pass you off to another specialist better for treating regular arthritis - even if there are plenty of oddities in medical history.
Go with your GP/PCP first. X-rays and MRI can be ordered by any doctor, as can blood work. Specialist have waiting lists, the more specialized their field the more months you will be waiting. A GP that already has your information could possibly have you in this week or the beginning of next. If you need a specialist after that than it speeds up the process as they don't have to order things like MRIs or blood work that could take a week to come back.
Make sure your lower back and posture is thoroughly checked as issues there are good at masking as problems elsewhere or even eventually causing knee and ankle problems.
I had knee and ankle pain as a young child, too. Dismissed as "growing pains" but in reality is simply some hypermobility.
If you were hypermobile, even just when younger, you'd probably know it and have been one of those kids who could bend arms, ankles, fingers, or legs around backwards or in weird positions to creep out friends/classmates and family.
As for not affording to be able to take time off... what can you do if you're having difficulties walking as it is? Time off for knee surgery looks better than time off for "my knee hurts", too...