Rf was 20.6 (normal 20) and crp was 0.62 (normal 0-0.49). all other blood work normal. i have symptoms of ra. pain in multiple joints, low grade fever. rheumatologist says i have ra. is this a strong indication that i have rheumatoid arthritis?

Although a "RF of above 20" is considered elevated, and RA is certainly possible, there are other conditions which mimic the symptoms described. Getting a COVID test or influenza test may explain your symptoms if positive.

If your rheumatologist said that you have RA, that is the same as saying you have rheumatoid arthritis. RA is just a short form for the term rheumatoid arthritis. Wish you good health!