6-7DPO feeling like I'm out 😔

I know you're not out until AF shows but for some reason since last night feeling like it's not going to happen. I'm so in love with my 13mo and want to give her a sibling and was convinced after ovulation that yes! we did it and now just thinking AF is going to show up instead of a BFP. How do you not get discourged during the TWW?