Heartburn?

I'm currently on cycle day 29, my cycles have been between 30-35 days lately, so I don't consider myself late yet. But for the last five days or so I've been having the worst heartburn and indigestion 😩 I've only ever had heartburn once so this is really strange for me. Has anyone had heartburn/indigestion/bubbly stomach as an early symptom? I live in the middle of nowhere and won't be able to get a pregnancy test for several days so I'm playing the waiting game to see if AF comes before I can pick one up. Thanks ladies!