How do you know when to start trying?

I've been married to my amazing husband for 5 years, and we are crazy happy. He just finished grad school, and started a new job in a new city, and I'm still looking for my next career move after the relocation. We were hoping to have both of us work for a year, to pay down some of our debt and start saving for our first house. However, my job hunt has proven to be much more difficult than I anticipated. We are both almost 32-years-old, and I've been taking pre-natal vitamins and tracking my cycle for the last year, so I would be ready when the time came. Lately we have been discussing the possibility of starting the conception process now- ahead of schedule. Nothing about our life together has really gone according to plan, and I'm worried that I will run out of fertile years before we've had the 3 kids we both want. My husband and I both had difficult childhoods, and it's important to us that our children are provided for well, including a quality education, and eventually the college of their choice. My question for you lovely ladies is, how do you know when the time is right to dive in to parenthood? I'm such a planner by nature- how do you weigh finances and practicalities against your own heart?