I got pregnant when my son was a baby.

I sat in a mini-gym class at the temple nearby with a baby in my lap and another one under it. I hadn’t told anyone. It was as if I had swallowed my secret, and my secret was growing.

The mornings were led by a woman named Bee. She helped us through our game-changing, life-changing, body-changing time.

One mother came in that day crying. “Try to explain why you are upset, Margot,” Bee urged.

“I’m not upset, not really, I just don’t know what to do with it.”

“With what? Keep going.”

“It’s like I am in love with her,” Margot pointed to her baby, spitting bubbles from a tiny pink mouth. She put a hand on her chest. “It’s like she’s my soul mate.”

I looked at my baby boy. He was full of cherub loveliness, barely talking, almost walking, a perfect echo of my husband’s soul. He reminded me of me, but not a lot. He was soft, with a peach belly that folded over his diaper like the top of an overstuffed envelope. He was the outwardness of my insides. He was it.

“So what do I do with that?” Margot pleaded, more to the group than to Bee. We all looked at Bee. She looked back at us, but did not answer.

And all I could think was: How could I possibly love another one as overwhelmingly as I do this one? How could I tolerate the inevitable comparisons between them, between my emotions? Put simply: How could I do this again?

When I saw the test’s two blue stripes that second time, even though we planned it, it threw me. I stepped back. I doubted everything, and I told no one. With that secret inside of me as well, I began the nine-month wait to meet my daughter. I was terrified I would fail her, that I wouldn’t be enough. I wouldn’t love enough.

When she flew into life, I knew her instantly, and loved her instantly, of course, just as much as I loved my first. She was pink and wrinkled, bigger than any baby I had ever seen. Eyes squinted, head pointy, body covered in soft white scales; she was the loveliest thing I’d ever seen. Her hands grabbed my hands, and her face fit into the curve of my shoulder, resting there.

And though I was relieved to know that I loved her with the exact same level of bone-crushing fervor I loved my son, lately it has occurred to me that the love is still different.

I love my first with the love of firsts. The breathtaking vastness of Cape Cod beach in the very early morning. The first day of camp, friendless and waiting. The overwhelming relief when the girl with the long blond braid sitting cross-legged said hello. The gulping breaths of the first time the swim instructor let go. Driving alone right after the test. My first beer. The wonder of a preteen boyfriend, his cold hand running across my cheek, softer and subtler but still like a slap.

I love my second from a whole different angle — from the soft place of experience. The golden beach at 4 p.m. A lifetime of friendship with the girl with the long blond braid. The fluid strokes in the pool, finishing a lap. Driving cross-country. Drinking a martini. Marriage, years in, a comfortable kiss in a messy kitchen.

Firsts are different from seconds because they are new. Seconds are different because they are practiced. These aren’t revolutionary thoughts, of course, but they are for me when it comes to my children.

When I first thought of this, I mentioned it to a friend. She was outraged.

“You can never talk like that,” she said. “You certainly can’t write that down. One day your kids will be able to read, you know.”

“But do you, can you, love them both the exact same way?” I asked her.

“Without a doubt.” I was ashamed. How could I even explore this kind of thinking? Of course I love my children equally, the exact same amount. Of course I do. But I do not love them the same.

Clearly they are different, my son’s and my daughter’s experiences, and development, and life. And maybe that’s why it’s O.K. for me to love them differently, as long as the amount matches. I can’t change their order, just as I can’t change their souls. I wouldn’t want to.