Has anyone here also struggling with Lupus and DVT at the same time

My name is Anna, 28 yo. I was diagnosed with blood clot in may 2017 and lupus feb 2018. I also have tendonitis, arthritis and varicose vein problem. I am in medication, Plaquenil for my lupus, Xarelto (blood thinner) for my DVT. My concern right now is I am having flares on my left calf for a week now. I don’t know why? I went to ER and the doctor said they found no blood clot on my ultrasound ( thank god) but why do I still feel the pain and flare on the same spot until now? I’ve never felt this pain this long before and I am wondering if it’s because the cold weather that just started here in Canada. I don’t know... please if anyone has the same problem as me I would like to know how you handle this problem. Thanks

Anna