Bad stomach pain along with other symptoms

For about the past three weeks I have waken up to very bad stomach pain. About a week or so after the stomach pain started I started to get pains in my lower back. Then my breasts started to feel a little sore. The breast pain is on and off but just about a week or so ago I started to feel pain in my back just below my shoulder blades. So this morning I woke up to go to the restroom and again I was in lots of pain. Only this time it was difficult for my stool to pass. Then about 30 minutes later I use the restroom and the stool is runny. So we have abdominal pain, lower and upper back pain, tender breasts, and stool. And if I might add I've taken two pregnancy tests one on the 14th of December and one on the 26th both were negative. Someone wanna help me out here? Thanks lol