Am I in labor?

Ok, so yes this is my second baby but last time I was induced.  I didn't have any of the worries about where my waters would break and how I would get to the hospital so this time it's freaking me out.  I like to have a plan and know how things will pan out and while I know this is completely impossible with something like a natural birth I still want to know how it's going to happen. 

The thing is, even when I was being induced I didn't realize that the period-like pains I was experiencing were contractions.  I had read books and atteneded the antenatal classes but I still didn't think anything of it.

So now everytime I get a twinge I start wondering "Is this it?"  The last thing I want to do is take numerous unnecessary trips to the hospital but at the same time I want to make sure that I get there in plenty of time. 

Because I will be treated for Group B strep when I go into labor my midwife has advised me to call the hospital when I go into labor and to head to the hospital when my contractions are 15 minutes apart.  Ok, so there's a plan but unfortunately I'm not very good about keeping track of things... like my period for example.  Some people know when theirs will come down to the hour, I usually have about a 7 day window of when I expect it.  This very problem led to my midwife and I having conflicting ideas of when baby would be due... I am happy to say that the dating scan backed up my guesstimate. I suppose that I'll have to organize myself and make sure that I am able to time my contractions when the time comes, I know it will give me peace of mind and probably help me get there in time and avoid giving birth to my baby in the hospital parking lot. 

Thankfully I've found some great tools to help track contractions.  For those of us who have iphones there is a fab app that only costs £0.59 which will time your contractions for you.  Unfortunately my husband has decided that this ingenious piece of technology does not warrant buying me an iphone... I'm still trying though.  So, after some research I have found this:
http://www.thebump.com/calculators/contraction.aspx
a contraction calculator available on the internet.  Now all I have to do is make sure that I am near a computer when I go into labor!