I think I'm in labor

I woke up this morning feeling really crampy and tired. I was still sore from the membrane stripping yesterday so I didn't think much of it. I went to work at 10:00am and after about an hour or two I felt this tingly feeling in my back. It didn't hurt, but it was starting to get annoying. I decided to start timing them to see if there was a pattern and sure enough every 6-7 minutes my back would tingle. After an hour I called my doctor to ask if it could be early labor. The nurse told me to keep timing them and when they got to 5 minutes apart for an hour to go to the hospital to get checked. I stayed at work until about 3pm when the contractions were starting to hurt and I couldn't sit comfortably anymore.