bbt temperature & pregnancy

were so happy that for 3 yrs.we find out that i am pregnant,but now im so worried,im 4 weeks,5 days pregnant but the doctor said she cannot see anything and told me to come back after 1 week.i feel pain in my left lower abdomen twice,but no bleeding,and i still check everyday my bbt temperature and its starting to fall down from 37.2,38,and now is 39.february 28 is my first day of my period until march 3(last march 13 is my lowest temperature(34)(day 14) and get high on march 14(38)that possibly i concieved.please help me, i need someone who can explain to me,do i have a coming problem and do i have to worry?almost everyday i cry because of too worry.