During a transvaginal ultrasoud looking for a missing IUD, will the sonographer be able to detect pregnancy?

I had a Mirena placed in feb 2011 an now it is "missing" and i am having symptoms of pregnancy. I am craving food, nauseus all the time, tired and bloated. I also have heartburn which i NEVER get unless i'm pregnant. I go today for an utrasound to find the IUD, but i want to know if i'm pregnant, the urine came up negative but i think i'd be too early for it to show up. I'd only be 3 or 4 weeks at the longest! please let me know if they will tell me!! ( my youngestwas detected by blood test at 2 weeks AND by ultrasound at 3.5 weeks so thats why i want to know if they will tell me!)