Hello, and I hope I can help you today. Pregnancy symptoms vary widely between women, and the symptoms that are commonly associated with pregnancy can also be caused by hormonal fluctuations. This can give you bloating, breast tenderness, irregular bleeding, mood changes and nausea even when you are not pregnant, and cause your period to be delayed or a different quality than your usual cycles. The most common sign of pregnancy actually is the absence of a menstrual cycle. So if you have had some bleeding and your pregnancy tests have been negative, you are not pregnant. Your diarrhea may mean that you are sick and your body is under stress which may be the reason your period was late. I suggest seeing a GYN doctor if your period continues to be irregular for testing of your hormones to determine the cause. I hope I was able to adequately answer your question today and that my advice was helpful. Best wishes, Dr. Brown I hope i