Just wondered if anyone had any advise or experienced the same thing..

I am 2 weeks and 4 days late for my period, i went to the doctor at 1 week late, she said she was confident i was in early pregnancy, she said to leave it a week and then test again; she said she would of expected my period within that week if i wasnt pregnant. Anyway just over a week passes and that brings me to today, i have been experiencing nausea, backache, headaches, sore boobs, indigestion, bloating and extreme tiredness, so i went back to the doctors after another negative test, she said she is still confident im pregnant and examined me internally and said everything is as it should be. She didnt want to do a blood test yet and wants me to wait another 2 weeks before testing again, she worked out from my dates that i would be 7 weeks pregnant on thursday! Has anyone experienced this and been pregnant but had negative tests. She said in some women this just happens and the hormone is so low it never detects it! Need advise!❤