how many dpo should I test?

Sarah • God 1st🙏 23 years old married to my awesome hubby for 4.5 years💍 momma to two little boys- 3 & 2 years old 💙💙 Angel mommy to Ruby Hope👼💗 Due with my rainbow in Oct. 2018! 🌈💕💜

just wondering when I should test? on my TWW;)