Best time to test

We have been TTC and my hormones have been crazy lately, nauseous, dizzy, headaches... the other night I bursted into tears for like 30 min. AF is suppose to make her appearance today but hasnt yet and I just wanted to test to see. It was a BFN but these symptoms have been like this for 2 weeks and my regular AF hormones are never this bad. I know I probably tested a little early but just curious on when the best time to test is?