How many DPO..

How many DPO do you start testing? I am 8dpo right now. I took a test yesterday. I knew it would be negative. I did it anyway. Like I couldn't not test. I feel like I know this month it's gonna happen. Ugh. So when do you test? Do you wait to miss AF? What's you're brand of choice? I have some 88 cent tests from Walmart. I want to buy some FRER but they're so pricey. And I'm afraid I'll waste them. Lol. I tested so much when trying for my daughter. My ex cut me off. But I feel like I have to get this right. I have 2 littles. DH has none. Here's to hoping it's this month.