This is tough for a lot of women. It was for me as well. Before you go into labor you may lose your mucous plug (for some women, it comes out while they are at the hospital- for others, it happens at home). The mucous plug is usually a thick brown or opaque white with strands of blood in it. It can come out over a period of a few days, or it can come out within hours. Usually, after this comes out, (generally speaking), most women go into labor with 24-48 hours or so.
Having diarrhea is common before labor as well. The thing to remember about contractions is this: longer, stronger and closer together. If you are having true labor contractions, you will have them while you walk, while you sit, while you lay down (you get the point). False labor (although it is preparing your body for real labor), will include lots of Braxton-Hicks contractions, but they will go away when you stop moving or change positions.
Your body sounds like it is in the getting ready phase. My advice to you is to watch for your mucous plug to come out and if your contractions do start coming more regularly, time them. My OB advised me to call after an hour of having regular contractions that were 5-10 min. apart.