Period symptoms while pregnant?

Has anyone ever experienced period like symptoms when you would normally get your period while you are pregnant? Although I am pregnant I am getting the symptoms I would get when my period was approaching...hope this question makes sense. I know period symptoms and pregnancy symptoms can be similar but I mean how some women a week before there period might poop a lot, or be really thirsty, or crave a certain food for a day...all signs that af was on her way...