Im i pregnant? im confused!!?

Ok so i get my period every month the cramps and all bt this month i didnt get anything not so much as a bad cramping or anything my period was suppose to come on the 20th it is now tha 29th i have real bad sore and sometimes light pains bt not cramping pains on my lower part of my stomach i eat and less then 20 mins im hungry again i took to PT test both negative and idk im very confused never had this happen to me before i ask my doctor if it was stress he told me its rare i was told to come back another week im 20 forgot to mention bt please help me if you can thank you!