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At 5'9," 140 pounds, and 36 years of age, the stats were on my side: I was nearing my 40s, but in what I'd consider the best shape of my life.

Physically, I felt great. I worked up a sweat running, at barre class, or learning pole fitness-the latter of which I'd even entered a competition for. But, mentally, I was a ball of stress. I'd made it through a divorce, moved to a new town with my daughter, and embraced a new title: single working mom. My writing career was booming. I had a new book on the horizon, and regular TV appearances. But at times, I felt the walls closing in. (But hey, as tough as everything was, at least I had my health.) That is until one day, the walls became those of a hospital room.

But let's start from the beginning: a Tuesday morning in June. The summer sun was shining and I had a busy day lined up. As I headed out for the first meeting of the day, I noticed sharp pains in my side. I chalked it up to a muscle strain. After all, I was often strained after a rigorous pole fitness session. But while trekking through Manhattan, the pains moved to my back; later that night, to my chest, to the point where I saw stars.

I considered a trip to the ER, but didn't want to frighten my four year old. I remember standing in front of the mirror in my PJs reasoning: I couldn't possibly be having a heart attack-I was much too young, too slim, and too healthy. I knew I was stressed, so I entertained the idea of a panic attack. Then I settled on a self-diagnosis of indigestion, took some meds, and fell asleep.

But the next morning, the pain persisted. So, nearly 24 hours after my symptoms started, I headed to the doctor's. And after a couple of brief questions-the first of which was, "You're over 35 and on the Pill, correct?" my doctor sent me straight to the ER for a scan of my lungs to "rule out" a blood clot. Along with other risk factors-none of which I appeared to have other than my age-the Pill could cause blood clots, she said.

According to Lauren Streicher, M.D., the likelihood of a blood clot for a woman who's not on birth control pills is two or three for every 10,000. The likelihood when on birth control pills is eight or nine for every 10,000 women. That was just a worst-case scenario though. I'd simply be sent home with some pain meds, I thought.

When I arrived, I was fast-tracked to the head of the line. "We never mess around when it comes to chest pains," the nurse explained. She went on: "Even though I doubt anything is seriously wrong with you other than a pulled muscle. You seem so healthy!"

Unfortunately, she was terribly mistaken. A couple of hours and one CT scan later, the ER doc delivered frightening news: I had a large blood clot in my left lung-a pulmonary embolism-which had already damaged part of my lung in what's known as an "infarction," cutting off blood flow for an extended period of time to the bottom portion of the organ. But that was the least of my worries. There was a risk it could move to my heart or brain where it would surely kill me. Clots often form in the legs or the groin (often after sitting for a long time, such as on a plane) and then "break off" and travel to areas like the lungs, heart, or head (causing a stroke). The doctor informed me I'd be put on intravenous Heparin, a medication that would thin my blood so the clot wouldn't grow-and hopefully wouldn't travel. As I waited for that medication, every minute seemed like an eternity. I thought of my daughter being without a mom, and of the things I'd yet to accomplish.

As doctors and nurses pumped my blood full of IV blood thinners, they scrambled to figure out what could have caused this. I didn't look like the "usual" patient on the cardiac care floor. Then, the nurse confiscated the package of birth control pills, and advised I stop taking them. They "could be" the reasoning this was happening, she said.

Most women I know worry about gaining weight on the birth control pill, but fail to recognize there's a laundry list of "warnings" on the label. One tells you there are blood clot risks for smokers, women who are sedentary, or over the age of 35. I wasn't a smoker. I certainly wasn't sedentary, and I was just a hair over 35. The label also mentions genetic clotting disorders, though. And soon, doctors told me they would test for a gene I had never heard of: Factor V Leiden, which causes those that carry it to be predisposed to life-threatening blood clots. Turns out, I have the gene.

Suddenly, my life was a new set of stats. According to the Mayo Clinic, both men and women can have Factor V Leiden, but women who have it may have an increased tendency to develop blood clots during pregnancy or when taking the hormone estrogen, commonly found in birth control pills. It's advised that women who carry this gene do not go on the pill. The combination can be lethal. I'd been a ticking time bomb all those years.

It's estimated that about four to seven percent of the population has the most common form of Factor V Leiden known as heterozygous. Many either don't know they have it, or never experience any abnormal blood clots from it.

A simple blood test-prior to going on any hormone therapy-can tell if you have the gene and are unknowingly at risk, as I was. And if you are already on the Pill, it's important to know the signs-abdominal pain, chest pain, headaches, eye problems, and severe leg pain-for clots.

I spent eight long days in the hospital, but emerged with a new lease on life. At first, I was in rough shape-excruciating lung spasms, and bouts of coughing up blood, as the clot began to dissolve. But I got myself back into fighting form (now I focus on weight training and cardio activities that carry minimal injury risk), and was determined to regain control of my body.

I've got to take care of myself first and foremost, so I can be the best mom I can be. It's something I'll have to live with for the rest of my life, with a daily regimen of blood thinners and regular doctor visits. I've also had to reconsider my method of birth control since anything hormone based is out.

But I write this today as one of the lucky ones: I was diagnosed, and live to tell about it. Others haven't been as fortunate. I've since learned that pulmonary embolisms kill one-third of the 900,000 people who develop them each year, often within 30 to 60 minutes after symptoms start. Celebrity stylist Annabel Tollman, a fashion industry friend, died suddenly last year at 39-reportedly of a blood clot. It is not known whether or not she was on the pill. But since then I've learned of more and more women who've been affected.

As I researched and shared on social media, I came across women who shared my tale, and headlines that screamed, "Why are young and healthy women dying of blood clots?" Knowing that doctors give out birth control pills like candy (around 18 million women in the U.S. reportedly use them), it's important to discuss any potential risk factors before going on it. Family history, blood tests, and simply speaking up are all crucial parts of a decision. The bottom line: When in doubt, ask.