Menstrual-like pain/ third trimester pregnancy?

I am 33 weeks with my second child. I have been experiencing menstrual feeling discomfort in my stomach for over a month now, I never experienced this with my first child but I have heard it is normal. Now today all day I have been having menstrual cramp feeling in my stomach but what is worrying me is that it is getting more painful (not excruciating, just feels like I have my period) more consistently throughout the night. My first child was 2 weeks late so I do not know what to expect with this one if it will come early or what. Does this sound like possible beginnings of contractions? This is nothing close to what I felt with my first child, I had no menstrual feeling pain with him. Any suggestions are appreciated