I am 33 weeks pregnant and have been having constant cramping today. I also have some dull lower back ache. Just want to make sure this is normal.

Is there a tightening in your stomach? I would contact your doctor. They most likely will want to see you to be sure everything is normal. It sounds like braxton Hicks contractions to me, which are completely normal, but It is always best to play it safe. Babies really need those last few weeks inside momma. :) good luck!