someone talk me down!

So I'm 31 been ttc #1 for 7 months but only second month using opk. According to my opk I ovulated around feb 15th and af is not due March 1/2.  How many dpo can I start testing? I bought a bunch of cheapy tests and am dying to start testing tomorrow but is it just setting myself up for disappointment? Tww is killing me please someone help me wait a bit!