Pregnancy test 9 DPO??

Kaitlyn • Surprise! Baby number three on the way! Twin sisters who are about to both become big sisters!
Hey! TTC #2 and I am 9 DPO.... I couldn't wait so I took an EPT (first response 6 days before missed period) and it was negative. 
​Did I test too soon?? Someone please help lol how many DPO should you wait to test?