Are we moving too fast?

My boyfriend and I have been together for almost a year. We bought together and always talk about getting married and having kids. We both really want to start trying for kids, but my parents are against that whole idea. The problem is, I’m only 18. My boyfriend is 27. We know it is a big age gap and we also know that it is a lot of hard work to raise a child. We are both sick of hearing about how much time and money children take. We know that it is not easy. I will have my nursing degree in the next two months and he is in Management at Walmart. Is it really too soon to try for kids? I’m just so scared of the judgement I’ll face from my family. His family is totally on board with it.