Your platelets, if low as well, might cause nosebleeds. I would avoid aspirin, ibuprofen and naproxen until you know your platelet count (on CBC) and all this is checked out. Lupus is the main autoimmune condition but I would caution you not to try to second guess this, as it will cause more worry and stress. The hematologist will consider and test for all possible reasons and you should know something soon. Hopefully it’s something simple and easily fixed like a medication side effect.