How do I tell my parents?

I'm 21 and my partner is 24. We've been together for 5 years now and been living together for just over a year. We earn £40k a year between us, we're very happy and been TTC since we moved in together. His parents are so excited to have a grandchild but I haven't told my parents we're even trying. I know they will be judgemental and upset because I haven't travelled or had many holidays etc... When we do finally get that BFP I'm so scared to tell them. Anyone else been in the same boat? xx
EDIT: does anyone disagree and think we should wait? I'd be keen to hear your opinions too x