Oh god, wait till you actually miss your date! I tested 3 days early and got a faint line, then ended up with twins, so double the chaos. Better to wait so you don't get mini heart attacks.
According to my Flo tracker, testing 1 or 2 days after missed period gives 99% accuracy. I waited exactly till day 31 of my cycle and got a solid positive. Track your cycle closely, it helps!
My MIL told me to wait at least a week after missed date because "jaldi jaldi me galat result aata hai". Honestly she was right, waiting a few days gives a very clear dark line.
If you're already feeling nauseous, wait until the day of your missed period. I was puking before my missed date and got a positive right on the first day. Best of luck, hope it's positive!