I thought I was done having babies. But I also couldn't deny the feeling of our family being incomplete.

• After having two children and putting away the baby stuff, I realized I was not ready to be done.
• I worried about our finances, my age, and my attention already being stretched thin.

After I watched my 4-year-old son William, dressed as a rabbit, sing "Here Comes Peter Cottontail" in his spring show, I sat in my car and cried.

Only one more preschool play, and this will be over, I thought. He will be in kindergarten at the public school, the building where the big boys go.

I knew that morning I wasn't done with babies yet. While many more wonderful and woeful adventures in motherhood awaited me with my two sons in the coming years, my head was finally beginning to understand what my heart had been saying for months: I am not finished. I want another baby.

Age, money, and emotions got in the way

There would be obstacles of course: financially, emotionally, physically. I was over 35. I knew there was hardly enough of me to go around with two sons, a husband, a house, and a career. And yes, I thought I was done with the baby bottles, poopy diapers, Fisher-Price toys, and late-night crying.

I'd packed away the little clothes, the potty seat, and the bibs and blankets. Although I tried to convince myself that it would be easier, more manageable, more affordable, and quieter with two, I couldn't stop looking at other people's newborns, especially when they looked similar to one of my boys.

As I passed a mother at preschool toting her infant carrier, I stretched to see inside and then made silly smiles at the baby snuggled there. I stared at blue-eyed infants in the advertisements, on television, and on cards at the store. I got weepy when I heard a teeny, tiny baby wail in Target.

While Will and I were food shopping, he pointed to a baby in a neighboring cart. "We gotta get us one of those," he said loud enough for the other mother to hear.

The woman and surrounding customers laughed as I did. I pushed the cart on, but I kept thinking, "I know."

Another morning Will asked when Daddy was bringing home the new baby. When I chuckled and brushed his comment off, he asked, "How do we get one?"

I had love for another baby but was also scared of starting all over again

Later I wondered about the what-ifs. What if I was too old or got too stressed out or we ran out of money? What if something horrible happened? As a mother of two, I was familiar with the work of pregnancy, the miracle of birth, and the fear and loss of control that comes along with them. But deep down, I knew the mystery was part of the magic.

I had the love in my heart for another, and the yearning wasn't going away with each passing day no matter how much I tried to logically convince myself more might be too much. At night in bed right before sleep, the familiar feeling of being unfinished slipped in. It was the possibility of another vibrant, energetic child. The tide had indeed changed for me.

I feared that if I did not listen to the little voice, I would be one of those women in their 50s I'd met at parties who said wistfully, "I should have had another baby."

My husband had been on board with this baby business since Will's first birthday. We always planned on a bigger family, though I don't know if he grasped the gravity of the potentially circuslike situation. Nonetheless, we decided to give it a go.

I opened my heart to the possibility of another beautiful being. It felt wonderful. It felt right.