Skipped Period HELP

Teresa

So my last period was between March5-10th.. I’ve been sexually active so when I missed my period in April I tested ASAP for being pregnant.. my test result at home was positive. I made a clinic visit to confirm and they did a urine test and ran it 3 TIMES AND ALL TIMES CAME BACK NEGATIVE. I wasn’t at peace so I went home and took another test at home and again POSITIVE. I waited 2 more weeks and went back to the clinic and they tested me again AND NEGATIVE AGAIN, also took a vaginal ultrasound and they couldn’t find nothing. At this point I was confused and stressing about if I was pregnant or wasn’t. I went back home and took a few more test and I still showed positive. On one day it happened that I had Tan Brown discharge, I was thinking I AM PREGNANT WTH. I went in AGAIN TODAY to the clinic and they ran my urine again! 4 TIMES AND NEGATIVE!! I asked if I could please be blood tested and the doctor spoke to me and said their tests were pretty accurate and would pick up the hormone quick even if it was just a bit. They didn’t take a blood test or anything and the doc told me if I had changed a diet, been under stress and I have been really stressed... can it really cause my period to be THIS LATE? I’m hoping to get it this month, my boobs are much more perky and again makes me think AM I PREGNANT?!