Am I really pregnant?

I am supposedly about 7 weeks pregnant but I do not have normal symptoms that preg women usually have. Checked with a doctor when I was 5 weeks, but can't see the whatever things that should be seen. She did say it's possible to see/not. I am just curious, is it possible for me to not feel anything other then my breast feels tender and sometimes sore? (The docs ask me to check with an expensive preg test. I did and it comes positive but still could'nt believe it. First pregnancy and all)