How early can i take a pregnancy test?

Okay so i had unprotected sex on 06/05/16. My period is irregular but i had it twice last month. 05/03--05/08 and then again 05/24--05/28. Im quiet paranoid that i could be pregnant. The side of my boobs where hurting 2 days ago and my sister says it could just mean im about to start my period but ive never had sore breast as a symptom that im about to have my days .. ive also had a few cramps but then again it could mean im about to start ..Although my partner pulled out before he came im aware of the whole pre-cum can still get you pregnant kinda thing. I have a clearblue pregnancy, and i want to know how early can i take it with it being 99.9% accurate wether i am or not prego.

PLEASE HELP.

Not really planning on being pregnant right now. Im only 17. And yes i should have used a condom or some type of birth control so i wouldn't be in this spot i get that now. I just need help