New to Migraines, Need Advice

It depends. Migraines can last weeks but everyone is different. Have you been diagnosed officially? There is a lot of medical uncertainty in your message. I'm a migraine sufferer myself, but I'm also a medical student very close to being a doctor so your question causes me anxiety. From just what you said most likely it's migraine, but there's a small chance it isn't, so it's very important you have proper diagnostics. The length of time isn't a useful part of the diagnostic algorithm though, it is too non-specific (many things present the same way). More important things are the exact symptoms you experience, your age, your family history, what causes the headaches, and what makes them better.

I've had them last up to a month before. If its not bad some excedrine helps me if not I've gone to the er before and they've helped a lot