What Are The Reasons For Nausea Vomiting Heartburn Stomach Pain And Mucus Like Discharge?

Hi, I am Tabitha and I ve been having nausea, vomiting, heartburn, sore tender enlarged breast. I started my period on July 30 and was off of it by August 1. Well normally I go 5-7 days and this time it was 2. I had a brown discharge mucus like discharge for like 3 days after that and then like a mucus discharge a week after that. I have been very tired, pains in my stomach, and lower back. I took a pregnancy test last Tuesday and it was negative and the dr did one on Wednesday of last week and it was negative. So they said wait a week and retest so I took one today and it was negative. Please help thanks!!!!