Thank you for reaching out to the EmpowHER community and for sharing your question.
The symptoms that you describe are early pregnancy symptoms or could just be indigestion. It's hard to say without a doctor's exam. A home pregnancy test would certainly be accurate by now. Scary as it is to take one, it can also take away your worries if you are indeed not pregnant and just having mild indigestion or a little flu bug.
Brown spotting can be a sign of implantation bleeding. Here's some information on what implantation bleeding is https://www.empowher.com/pregnancy/content/pregnancy-words-implantation-bleeding-what-it-and-it-normal
twirlwhirl01, the only way to really know is to take a pregnancy test or visit your doctor.
I hope this helps! Best luck!