BBT and Period

I got my period June 9th and I stopped bleeding yesterday. Today I just have brown discharge. This is my first actual month charting for my doctor to make sure I am ovulating. When should I start ovulating and how does the bbt work while ovulating? Does it drop and then rise? I just need some guidance!! Thanks you for the help of anyone comments. I would love to conceive without getting on any medication!! Also when do I start opk testing? Also has anyone used Pre-seed too?!