Hello and welcome to the forum. Thanks for this question. Is there any update? It is obviously best if you see your doctor about this. Here are the symptoms of appendicitis https://www.mayoclinic.org/diseases-conditions/appendicitis/symptoms-causes/syc-20369543. This does not really sound like that issue though. How are you now?
On the one hand, if you've got the flu, you're sick and will be sick until you aren't sick anymore. On the other, if you're concerned, a doctor would be much more valuable to you than us. If it were appendicitis, I'd think the pain would be a whole lot more than what you're describing, but if you really think you ever do have that go directly to a doctor, not to a website. I'm guessing if you indeed have the flu, though, that's probably it, but when you say "a" flu, that sounds more like you've got some unknown virus or bacterial infection which, again, if it's not going away needs a doctor, as we can't examine you. Hope you feel better.