Irregular cycle

My cycle is very irregular but in the last year I feel like it has some what straightened itself out. My average seems to be about 58 days or every other month. But sometimes it still doesn't come. I recently bought an opk and wondering when I should be taking the tests. Should I go by Glows predictions or just take a test every day to find anything. I would really like this to work. I will be 28 this year and married for 5 years in September. This is baby #1. I am past ready for a baby!