possible contractions at 28 weeks?

marinewife42

I am 28 weeks and 4 days and for the past couple weeks, sometimes after sex, sometimes just out of nowhere I will get this tightening in my lower abdomen that is actually really painful and makes it very difficult to walk or move too much. I wasn't too worried and just thought they were probably Braxton hicks, which they probably are, but they have been getting more and more painful every time i get them and tonight I timed them and they are pretty regularly 2 minutes apart and last exactly 30 seconds. I'm not too concerned but maybe I should be?