Interpreting my BBT chart

Cara • Expecting our first baby Jan 1st 2016! Married my best friend after 8 years together 10/10/14.
Does anyone know a lot about these charts? Just wondering if mine shoes any information. I'm not sure how to read it. I had my strongest ovulation test on 4/7 although it was positive on 4/6 and 4/8 too they were lighter.