3rd pregnancy and very tired, sore, and craps

im on my 3rd pregnancy and iv been very tired, sore, hungry, and having craps. im almost 5 weeks. is this normal or am i having twins? iv tried to read up on diffrent things to find out why i feel this way and all i can come up with is either its because its my 3rd pregnancy or twins. i have doctors appointment next week but still would like some kind of answer so i know what to really ask. this pregnancy is very diffrent from my first 2.