Rheumatoid arthritis and Hydroxychloroquine?

I was just diagnosed with rheumatoid arthritis after having a successful trial with Hydroxychloroquine as it helped my pain and also dropped my CRP and ESR to normal levels (which were the only things that were very elevated). I have been feeling really great and have been really happy with the medicine, but had some questions. I actually didn't realize at first that I had swelling anywhere, which made me doubt a possible RA diagnosis. Since starting the medicine, I have noticed that inflammation that I didn't know was there, come down significantly everywhere. My rings are now falling off my fingers constantly, my shorts no longer fit the same because my hips are more bony now, I can see my knee bone, my ankles are slimmer, etc. My fatigue has also improved significantly. I do have pain flare ups every now and then, but much better than dealing with pain 24/7 like I was previously. My question is, has anyone else developed any new symptoms/new diagnosis after starting Hydroxychloroquine? Within the last few months I have developed other kinds of symptoms and am worried that the medicine/treating my RA may have triggered a different disease. Also, if my doctor diagnosed me based on elevated CRP and ESR levels, improvement of symptoms and numbers with medication, and my presentation of symptoms, how do they know for sure that it's RA and not lupus, for instance, since it can also be treated with Hydroxychloroquine? I've noticed they have very similar symptoms with Lupus obviously being worse, but since I've developed other symptoms, I've wondered if maybe it's lupus or like I said, if treatment may have triggered a different illness. I'd love to know everyone's experience with Hydroxychloroquine and what you may think!'

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EDIT: My rheumatoid factor, anti-ccp, and ANA all came back negative - which again, made me doubt the diagnosis; however, now that I'm feeling extremely better with the medication, I'm thinking the diagnosis is accurate.