There are a lot of different things that could cause a fever
that happens only periodically or only at night, which is why you should discuss your concerns with your doctor
. That being said, I would like to ask you more questions about your symptoms, because there are a lot of other things that could be going on especially with the nausea and vomiting
. The combination of fever, nausea and vomiting is a little bit worrisome. There are a lot of things I would think about in a woman your age. Even though you don't have other medical problems, you could be having the start of some medical problems with these symptoms, for example this is a possible presentation for diabetes called diabetic keto-acidosis. This could also be a food related or viral gastro-enteritis that is making you feel bad for a few days and would cause nausea and vomiting. There are more rare things that can cause a nightly fever that are called period fever syndromes, but these aren't diagnosed until you have had these symptoms for many months or years.
My recommendation would be to get a thermometer to measure your temperature and to see how high your fever is when you have it at night. In addition, if you are having any problems keeping food or drink down because of your nausea and vomiting you should go see a doctor or go to an emergency room. If the fever gets high, or any other worrisome symptoms occur please seek medical help immediately.