Ovulation Test Beginner.

This is my first time using ovulation tests and I started on CD 12, Friday the 25th. It's CD 17 and Glow says it's my peak day but I'm obviously still testing negative. Has anyone had their ovulation day past the time Glow said it would be? These tests are making me worry that I'm not ovulating at all anymore or maybe it's not in the timeframe I thought it would be. We are TTC our second child. With our first child it just happened when we were teenagers, and I've been on BC since my son was about 3 months and I couldn't breastfeed him anymore. I stopped BC in January before my husband deployed. He has only been back for 2 months now but I'm surprised I haven't gotten pregnant. Any advice would be helpful. :)