Am I wrong

My husband and I have been married for almost 6 months and I'm secretly TTC. I have only 1 child who's 7 and I'm 27. My husband wants to wait till I'm 35 before TTC. I think he's nuts. He knows i track when I'm most fertile to be sure he doesn't cum inside of me. But as of lately I've been lying to him and telling him I'm not fertile when I'm actually the most fertile. I no he will be an amazing dad, we both have jobs, I already have one child so I know what I'm getting myself into. I just feel bad for tricking him. Should I stop ?