Flip-flopping pregnancy testing

Amber • Had a missed miscarriage in June and a chemical pregnancy in July. TTC for over a year.
I have gotten a very very faint positive on Friday, a negative on Saturday, a vvf positive again on Sunday, and a negative pregnancy test again today. Wth. My period should be due tomorrow or so. I have been experiencing extreme pregnancy symptoms over the last several days but not really bad so far today and have just gotten a tiny bit of brown discharge in the last 12 hours. I'm losing my mind. I had a chemical last month but that was three days of vvf positive and then went negative. What is going on? Ugh.