Possible?

According to glow I'm 4dpo and my fertile window was 6 days long. I know it's crazy but I never ever get heartburn but last night I did. It was my first symptom with my ectopic last year followed by nausea waking me at 2am without fail. I had a crazy sharp pain on my lower right side too. Never thought I'd say this but I hope the heartburn continues. Im pretty sure glow was close to being right. So if it were it'd be too soon to have symptoms, right? Could be further past though so I'm going nuts. Chances ladies? How soon?