Irritable uterus

Well, I went to the midwives today and told them I was still having lots of contractions, and they decided it was time to do a few tests and make sure everything was okay.  So they orderered some cultures from you-know-where and a test called fetal fibronectin.  This second test can tell you with 98% accuracy whether you're going to go into labor within 2 weeks.  So basically they are ruling out that my contractions are preterm labor.  My cervix is closed tight as can be as does not look like a "laboring cervix".  And the test for leaking amniotic fluid was negative, so I'm probably fine.  Next question...why am I having so many contractions?  They call it a irritable uterus, which basically means you're having more than 4 contractions per hour that are not related to labor.  They are not painful, but are often uncomfortable and I have to hang out for a minute or so until they go away so I can go about what I was doing.  Other than that, things are peachy and I feel really good!