 [ Symptoms ] 6 days late i am 6 days late for my period i took a pregnancy test 2 days ago and it was negative i only have tender breasts and am slightly nauseous could i be pregnant should i see a doctor [ Disease ] just relax you simply have side effects of antibiotics like gastritis and acid reflux causing chest and stomach discomfort you should simply take antacids like milk of magnesia and also take empty stomach proton pump inhibitor like omeprazole till you are on antibiotics avoid spicy foods and take probiotics like yogurt you will be better soon hope this helps regards