What's the latest you got a positive?

My last period was June 6th. They are painful, clotty, and lasts 6 days...they are pretty regular for the most part. I had sex June 12th which was two days before my ovulation started. Soon I started noticing I been EXTREMELY moody. Nausea is my best friend but not just in the mornings, lower backache, I get up to pee alot during the night and I pee alot during the day, I used to love chocolate now I can't even stand the smell of it!, my sense of smell has heightened, and I occasionally have small headaches. July 2nd, I woke up to light bleeding. There was no cramps and this lasted 4 days, also there were no clots and I wasn't filling pads. it completely stopped after the fourth day, but my symptoms are still present. I would be 7 weeks and 5 days if I am pregnant. Now my skin has alot of darker patches between my breasts and my chest. I'm wet all the time (Sorry not to be gross), my areolas are darker and larger, my nipples are tender.. also last thing all my HPT have been negative and I had one blood test about two weeks ago that was negative. Doctor was real rude and when I explained to him everything, he told me I was crazy & how he went to school for this so he would know if I'm pregnant and refused an ultrasound. I know it's unlikely for a blood test to be wrong but I've been told to trust my body.... I have cut off alcohol and the few cigarettes I would smoke since the day I felt I was pregnant just in case..am I overreacting or should I still take precautions and treat my body as if I'm pregnant just to be on the safe side?