I knew mine we contractions, because they got so bad, where when you are having one you have to stop doing everything you were doing, because it hurts so dang much and you can't really concentrate on anything else besides getting through the pain, that's when my husband knew it was time to go to the hospital, but I kept telling him that it's false labour. This was happening every 5 minutes, I had to get down on all fours it hurt so bad. Denial is also a big sign (along with all the contractions) that you're in labour, he knew it from a book for a pregnant daddy he read.
I had the same thing 41 weeks, and Dr. stripedded mine too. Lost plug the next day. That is labor. I had my son after 24 hours of labor by c-section the next day. Good Luck.
If you feel your tummy (near the top) when you are having the pains, and your tummy gets hard for a period of time (60-70 seconds), then they are contractions. If it is your first baby, you call the doc or go in when they have been 5 min apart, lasting 60 secs, for at least an hour.
Sounds like you'll be going soon. Good luck.