Yup, once you are coughing you are less contagious (if it is whooping cough). If you do come down with a cough in the next weeks, it is a potential concern for the newborn, as you could theoretically pass it on. Although that would be unlikely, as you would be past the initial contagious stage.
You can be immune to whooping cough without the vaccine. It seems that adults regularly get whooping cough, it is just much more mild in adults, and goes unnoticed. You could be immune without knowing it.
Megan, mama to her little boy (Feb2008) and introducing our little girl (Dec 2010)