Morning stiffness and joint pain is related to Rheumatoid Arthritis most commonly.. There is a possibility of negative blood tests in Rheumatoid Arthritis.. There are some other Joint inflammatory disorders similar Are you taking any medicines currently..
Next Steps
I will suggest you to start with hot fomentation, take analgesic with anti inflammatory medicine,
calcium and vit d supplements.. You may require to start some specific medicines for rheumatoid arthritis if pain doesn't settle down..
Health Tips
You may plan to meet a Rheumatologist at nearby hospital to start DMARDs..