Hello, I hope I can help you today. First of all, any woman having unprotected intercourse is at risk for pregnancy. On addition, missing your period is the most common sign of pregnancy. Weight loss due to exercise can also cause you to miss your period, so there is no way to know if you are pregnant based solely on symptoms. However, nipple discharge can be caused by other hormone abnormalities that can also cause irregular periods. An excess of the hormone Prolactin, which stimulates milk production, can be produced as a side effect of medications or even from a type of benign pituitary tumor. Depending on your age, abnormalities of the breast ducts or even rarely, breast cancer, can cause nipple discharge. So if you have not yet done so, you should perform an over the counter pregnancy test and if the results are negative, I recommend you see your local physician for an evaluation of your hormone levels. I hope I was able to adequately answer your question today and that my advice was helpful. Let me know if you have further queries. Best wishes, Dr. Brown