I'm 36 weeks today. I had a doctors appointment this morning and she said I was dilated to a 2 and…

I'm 36 weeks today. I had a doctors appointment this morning and she said I was dilated to a 2 and asked about contractions. They were 15-20 minutes apart and not regular or painful at 10:30 this morning. They're still not painful, but they are more regular now (about 7-10 minutes apart for the past hour) and I have this weird pressure in my bottom. Should I be worried?