Back pain in the nipples does not necessarily mean that a woman is pregnant. It is possible for a woman to have back pain and nipple pain after pregnancy, but it is not possible to tell if she is pregnant by the symptoms of back pain and nipple pain. For example, when a woman is premenstruating, she may experience lower back pain and nipple sensitivity due to changes in her hormone levels. Therefore, if you are worried about the possibility of pregnancy, you can take an early pregnancy test more than two weeks after intercourse, or a blood test more than a week after intercourse.