You need to stick to BOTH of you being 30 and married.
If you have to ask the question you are TOO YOUNG to be having sex! Sorry, not to be mean but those that ask questions like that are the first ones to become or get their partner pregnant or get STD's because they are uneducated about sex!
Don't have sex just because everyone else around you is having sex. BE YOUR OWN PERSON. Hold off until you know that person, love that person, and want to marry that person.
There is nothing more selfless then giving yourself to a person that you know you won't be with in the future. You bodies like a car... STOP PUTTIN MILES ON IT...