You have to get it each time you are pregnant bc it is for the baby more than it is for you. The baby cannot get the whooping cough vaccine until 2 months so getting this vaccine protects them.
It's good for 10 years or the next pregnancy is what I was told. I got mine last minute at 36 weeks. I wasn't planning on getting it at all because I didn't feel it was necessary. Then I went into labor early and freaked out because I kept thinking of my premature baby having no immunity. So I went and got it.
@1sttimemommy84, as the parent I believe you are supposed to get it again. My family got it with my first son and it is good for 5 years.... I got it with my first son, and got it again this time...