Hi, and thanks for your medical question on eHealth forum!
Pain in abdomen with sore nipples can be due to pregnancy. Hence take a home pregnancy test, and if negative, go for a blood HCG estimation. The other possibility is an ectopic pregnancy, and this can give negative pregnancy test. The third possibility is polycystic ovary. Since a confirmed diagnosis cannot be given on net please discuss these possibilities with your gynecologist once. Hope this helps. Take care!