Late period by 3 days

Amanda

Hi , i'm late by 3 days according to my app and i took 1 pregnancy test and its negative . I've been experiencing some early signs of pregnancy like exhaustion, some nauseous on and off , sore nipples . could it still be to early to detect on urine test or should i go to the doctors office to get a blood withdraw? I wanna know for sure because i work with chemicals.