Waiting for concrete diagnosis..help

I am currently awaiting for the last peice of the puzzle to fully be diagnosed with having lupus....I have a very high positive ANA, the "butterfly rash" sensitivity to the sun, and now we are awaiting some blood and other test result to give me the 4th criteria. I also have swollen joints and such.
The dr has prescribed Plaquenil and I was wondering if it works, and what peoples experiences with it have been?? I am allergic to many medications and am hoping that I wont have the same problem with this...
Also has anyone with Lupus ever experienced heart arrhythmia?? I am very scared at what this could mean and the dr said she was 99% sure it would come back positive based on all of my symptoms and labs...
Can anyone share their experiences..I am only 31 and feel like I am too young to have all of these problems!
Any insight would be greatly appreciated..

First of all, don't be discouraged. I know it is so hard not to be when you are having so many aches and pains. It is always scary to hear the doctor say something is wrong with you. I was diagnosed with Lupus at 12. I was having chest pain, fatigue, generalized weakness. It progressively got worse. I ended up having pericarditis (fluid surrounding the heart) and had to have surgery to remove the fluid. Following the surgery, I had recurrent pericarditis that the Rhuematologist treated with prednesoine. That went on for about 8 years. I started college and began to learn more about the medicine I was taking and didn't want to be on the prednesoine anymore so I ended up switching doctors because my first Rheum wouldn't take me off of the prednesoine. You have to learn how to be your own advocate. A lot of times the doctors don't listen to you so you have to find a doctor that will. After switching doctors I have had very few flares. I was able to get off the prednesoine and have been on the plaquenil ever since. It has really worked for me.
I have been chest pain free for 2 years now! In the last 2-3 years I have now been told I have IBS, and Fibromyalgia. Once you get lupus it is common to have other things start to go wrong. I have had lupus for 12 years now, and my advice is to listen to your body. People always think they know their bodies, and everyone knows their body a little bit, but having an autoimmune disease makes your tune into your body like you never thought possible lol. It is so important to know when you need to stay home and rest instead of going out and when you can go out and feel fine. It takes a while to get to know your body but it is so important and helps to prevent flares. For a lot of people the sun causes the rashes that you have been having so wearing suscreen is really important. The swollen joints and aches and pains are what I struggle with the most right now and I have found that working out helps a lot with the swelling and stiffness. Stress is what causes my flare ups the most. It is hard to deal with a diagnoses at first but the most important thing is to listen to your body and find was to deal with stress. Dont' be discouraged there is light at the end of the tunnel, its just hard to see at the beginning.