My parents-in-law have been bugging me to have a 2nd child. I have told them I would like to wait for a little while long. How should I get them off my shoulders?

I suggest, if you are not able to put across that you do not like to discuss the matter with them or tell them that you don't want the second child right now, tell your husband to communicate it to them. I think, he will be able to make them understand better.