Horrid contractions.

I seriously don't understand. Since last Thursday I've had constant menstrual like cramping with one episode of about five contractions and ridiculous lower back pain. I got checked and was told I was fine. Which is awesome! Except it's just getting worse. I woke up from a dead sleep last night with a contraction that took my breath away. I had two more just like it spaced about five minutes or so apart and then they weakened and spaced really far out. The contractions hurt so incredibly bad I had to breathe through them and swore I was going into labor. How on earth can this be normal?!?!? I'm fine now with just cramping and feeling crappy. No more contractions. Normally I shrug off contractions because I have painful Braxton hicks. But these are without a doubt CONTRACTIONS. They always stop though. Why is this happening?!?!?