It still startles me that people make babies with sex. Privately. Easily. Fast. Then there's a birth, and no one looks back. For me, like many women, conception was an agonized, un-caffeinated blur of escalating medical procedures, followed by a pregnancy that seemed to last not the actual 36 weeks, but rather the whole 36 months it took to get there. The physical and emotional strain of those years lingers on into motherhood, like an inner mark as real as my C-section scar. Strange as it sounds, I feel more changed by the trials of infertility than by the transition to parenting -- and that's saying something, with my toddler twin boys turning 2 this month.

I still identify with infertility, as if it were a chip I'd been given in AA, though in AA, you can stay forever, whereas with the "TTC" community -- "trying to conceive," in online parlance -- you leave the minute you succeed. Parents of multiples flock together and offer tremendous support, both tactical and abstract, and many of the twin moms I know probably conceived like I did, with DNA mixed in dishes and delivered by needle. Nevertheless, issues of post-infertility stress aren't explicitly broached. Most twin parents practice prison code: you don't ask what anyone else did to get there.

When I lived in TTC-land, I had a term for mothers prone to excess oversharing: vagina ladies. Into this category fell any woman who used Christmas parties to talk about the details of gory birth or tricky breastfeeding, while childless me wiggled one leg nervously at the dessert table, gobbling a Santa cookie. How much were you dilated? My nipples cracked and bled! Even before I knew the extent of my infertility, I didn't think that baby-driven hardships should be so defining.

In reward for my foolish assumption, fate has deemed that I become a vagina lady myself. This is another odd dimension of my post-TTC existence -- becoming someone who would have once greatly annoyed me. I've got my double-wide stroller, the kind that used to make me shudder. Though I consider my twins a miracle, I like the miracle to sleep, and I sometimes complain when the miracle wears me out. Once, I would have considered this akin to whining about how my pile of money was so heavy it hurt my back to lift it.

I am grateful for my sons, and equally grateful to the people who stood by me on both sides of the parenting aisle. When my twins turned 1, a friend sent a box full of tiny clothes and board books. She, too, was battling to conceive, and her generosity humbled me. I worried what it had cost her -- emotionally, mostly -- because in my TTC-time, I would rush past baby store displays like those bibs and giraffes were bricks of uranium. I only bought toys that were packaged, which felt safer than actual contact, and I once delivered a boxed monkey lovey to a new mom neighbor with my hands visibly shaking. I dreaded holidays to an extent hard to explain. I wanted a war on Christmas, or at least a decent curfew.

Many people grow through infertility, but instead, I shrank. After a while, I stopped going to baby showers altogether, ordering a musical lamb toy online as a proxy for my presence, its fuzzy face trapped behind plastic. It was a perfect messenger -- sheepish, walled away. Finally, I tipped into an etiquette freefall of sending no gifts whatsoever. This is one of the worst parts of feeling like a victim, the way it fueled my bad behavior, and potent karma I'd soon face. Years later, when my mother-in-law sent out invites for my own baby shower -- for twins, no less -- I had to stop myself from launching a follow-up email apologizing, saying something like, please, don't feel obliged to come. People did come, though, with heaping bags of registry loot.

While wary of my own luck, I was also desperate for support. Tina, my best friend from college, had also struggled with fertility. Childless at the same time, we'd had long talks about the aggressiveness with which everyone around us seemed to effortlessly spawn. Then the calls stopped. With a lump in my throat, I read her email telling me she was carrying twins -- a complete shock, a natural occurrence. I cried, and hated myself for every salty drop. Her pregnancy wasn't a beacon of hope, but the light of companionship suddenly snuffed. Of course Tina totally got it, and told me it was OK if I wanted space. I stewed in my despair.

About a year later, I too found out I was pregnant with twins, through wholly high-tech means. Despite my long silence, I called Tina first. She cheered with heartfelt joy, just as I hadn't done for her. I didn't deserve her love, but I lapped up every ounce. This is part and parcel for me, the sense that I've been graced, while also wondering, why me? It's almost like survivor's guilt.

At the clinic where I conceived, people aren't supposed to bring babies into the waiting room, but someone was always whirling in with a carseat-bound infant. Now, I'd like to take our sons back there, too, but I never will, unless we can meet our doctor in the parking lot, perhaps behind a shrub. I still identify with those waiting women in sweatpants and flip-flops, leafing through magazines to distract from the endless wondering which way their lives will go.

That's why the infertility was harder than anything even my infant and then toddler twins have yet to dole out: the not knowing. As a twin mother I may be intermittently exhausted and occasionally overwhelmed, but it's nothing compared to indefinite uncertainty, the purgatory of TTC.