Everyone has good points and should take all that into consideration....it seems that you want to tell your parents. It's really hard to be completely certain about sexuality. It's funny yet extremely frustrating.
You don't say why you're worried about telling your parents, so, might help knowing why, but....pretty much, you just have to come to peace with yourself, let you be you, even if you don't say anything to anyone around. Just think of everything and relax and just,...get used to it fully?
Once you get a sort of confidence about it, it's easier, the rest of the stuff. Not that it's easy at all, even if you know for sure that parents or friends will be ok with it. It's scary because there's still that chance, because you aren't what you thought you were, and you might not be what you're expected anymore.
Next steps vary for everyone, just try to go with the flow of life, it all works out eventually, though if you feel the need to say for some reason, just, try to gauge their opinions on it, bring up all the samesex marriage articles or something, just, hint maybe? eh, it's what I was doing. I just need the guts to tell my parents, who, already know, and already like my girlfriend, they just aren't officially in the know. I'm just...scared of the questions.
It's different for every person, but..it does help to talk about it, or write about it. I'm a good listener if you'd like, I'm not so great with the advice but...it'll all work out in the end...It kinda has to. 🙂