From all your replies, I can only see you're angry and hurt cuz your ego has been challenged "for not planning".

Communication is the key for every successful relationship. If you're already planning then why not discuss with her to see if she agrees to wait another year? By then she'd be 32 already... u must know the agreement for not having kids are only a decision between you two and maybe her parents have no idea about this thus they are pushing you guys into marriage thinking about fertility rate. In this part you have to understand her, she is being sandwiched between her parents and you .... as her man though ur frustrated being viewed as not capable or not serious, you have to put it aside and concentrate on how to reach an agreement..... don't harp on problems but find a solution...