How to tell your parents?

I don't have a glow announcement yet but wasn't sure where to ask this question. When I do have the opportunity to tell my parents I'm expecting, how do I? I'm 30 and my boyfriend is 38. We've been together for a year and a half and we are perfect together. I mean, you know when you know right? Well, my parents aren't fans because he works a lot and they've only met him once. However, he has recently found a better job that isn't so demanding and will be able to spend time with my family more often. With that said, how do I tell my parents I am pregnant when I'm not married and have only been with him for a short amount of time?