Welcome to the lupus forum and I'm sorry to hear that you may have lupus. I'm not Doctor and can't say whether you have it or not. You do have some symptoms of lupus but you may not have it. Lupus is very hard to diagnosis is know as the disease of 1,000 faces. There isn't one specific blood test to prove you have it.
Joy showed you where to look at the 11 symptoms that the Rheumatologist uses to help them diagnosis us. You must have 4 of the 11 to get a diagnosis. Lupus varies from patient to patient, some cases are very mild to some very severe cases. Yes, you can have lupus w/o having a positive ANA, according to the Lupus Foundation, I believe they say only 10% of patients will test negative. I happen to be one of that 10%, I have had a positive ANA several time over the 26 years that I've had the disease. Normally, however, I test negative on my ANA and double stranded DNA.
Your GP isn't the person to diagnosis you, you need for him to give you a referral to see a Rheumy. Also, the Doctor's comment about prednisone makes feel better is pretty much true except for folks with Fibro. My hubby who doesn't have lupus was on prednisone for a severe allergic reaction to poison ivy, and his low back pain went away totally while on the prednisone.
If you have any questions, please free to ask away here. Lots of experience folks here with the disease. As you read about lupus, please remember, lupus isn't a death sentence at all. Most patients respond well to treatment. There isn't a cure for lupus but many patients go into a symptom free period, guess you could call it a remission. Good luck and I hope that you get some answers really soon. I'm very sorry about the pleurisy I suffer from the stuff all the time and uveitis a lot.
Try not to panic to much yet, wait and see what the Rheumy has to say. Remember, keep the journal of symptoms and try to stay out of the sun. Also, rest is a key thing in helping your lupus. Plenty of rest and low stress are very helpful to make you feel better.
DX- RA, Lupus, Fibro, LGL Leukemia, Pulmonary Hypertension, Bells Palsy, Gastroparsis, Blood Clots, Glaucoma, Chronic Pericarditis & Pleurisy, Severe Anemia. Way to many medications to list.