Why the Pressure?

I have just have a question and was wanting some thoughts.

Why do people find it okay to pressure people into having kids when they get married?

I have been married for 6 years in August and my husband and I have decided that we still aren't ready for kids. We are 25 so we got married pretty young. Which also means we have plenty of time left for children. However, our friends and family are always on our case about when we are going to be having kids. When people decide to have child should be a left up to those people not everyone else around them. Sorry this turned into a little bit of a rant.