Observation hospital tests

The Braxton-Hicks contractions have been starting earlier in the day and lasting until bed. I started wondering if it was normal. I spoke to the advice nurse and she advised that I go to the labor and delivery department at Sequoia hospital (where I will deliver in the near future). This was a bit unnerving for me, but I know they prefer to be safe than sorry. When I got to the hospital, they put two straps around me: one to monitor the baby's heart rate and I guess the other is to monitor my heart rate (?). I sat for an hour and a half listening to baby "Z"s heart rate. It was really interesting to hear that when I felt some pain (which I found out were contractions), her heart rate increased. It turns out that I have about 3-4 contractions per hour. The RN's stated that this isn't cause for concern, but I do need to be more aware of how frequently I get them over the next few weeks. My only thought is "Please don't deliver before we are able to find someone to cover me at work." I guess one of my worst nightmares is for me to have the baby before fully training someone and coming back from maternity leave and have to clean up and re-refine my job. Also, I would like to have a baby shower while I'm still pregnant! :)