Getting annoyed with this

I will be 8 weeks in a few days with my third child. My first one, I was 5 & 1/2 month before I found out and I was 18 years old. My second I was almost 4 months. With both tests came back negative over and over again. With my daughter I was getting test with blood and urine every week. Mainly because I was in combat and have kidney failure. The only way the doctors found my second child was by ultrasound and it was a huge shock to everyone. When I got back to the states two weeks later, I got orders going back because my tests came up negative. While it was funny then cause I was twenty, I'm 31 now and on hard medication for serious conditions. I know I'm pregnant but the VA will not help because I'm not testing positive. Any vets out there with any advice? Please!!!!!!