Understand BBT charts

Lindsey
Hi all!
I was just looking for some pointers. This below is my chart on glow. I have tried to understand this whole BBT thing but I still am confused. Because glow said i ovulated on the 6th? But fertility friend says i ovulated on the 4th? I got my first solid smiley face on the 5th? I just am wondering which day my actual ovulation took place. Also does your temp stay elevated at a certain temp if you have concieved?