I'm planning to use these test for the first time this month after being unsuccessful conceiving for many many months. My cycle is very irregular, ranging from 33-39 days so it's hard to know when to start testing. I have 20 tests. Should I start taking them early because I have no clue when I ovulate? I'm tempted to start testing around CD 12/13 and take throughout first cycle to make sure I don't miss it.