Make doctor test AGAIN!!!

I got my BFP on June 22nd, took another test June 25th, still positive, I've been having all the symptoms, I'm TIRED, & have nausea, I went today, July 8th to confirm with a urine test at the doctor & she said negative!!! I was so shocked! This is my 3rd pregnancy, I'm not stupid or crazy! Another nurse saw my face & took me to test again & what do you know! Positive! The first test was faulty!!!! Make them test twice when they tell you it's negative! I literally almost had a heart attack!