need help

my doctor told me a few months ago if i got pregnant id be high risk pregnancy last week i got a postitive test went to health department same day and got a negative they told me to retest so yesterday i tested again and got a positive. today ive been having minor cramps but they dont feel like normal cramps and now i have light bleeding. any idea what could be happening? has anybody had this happen and they end up having a normal pregnancy? im so nervious