A familiar presence at her mother Martha Stewart's side in both good times and bad, Alexis Stewart, 41, cohosts a talk show on Sirius Satellite's Martha Stewart Living Radio. With characteristic bluntness, she talked to PEOPLE's Mark Dagostino about her efforts to have a baby and the pain of infertility.

I wanted a baby when I was 37. But when my mother got in trouble, I couldn't do it, couldn't think about it. About two years ago, after all that was over, I got back on track. I'm single now, but having my own kid is the most important thing in my life, so I'm trying everything I can: fancy doctors, expensive drugs, high-tech procedures. Most people can't afford what I'm doing. I'm really lucky; I know that. I also know it would have been infinitely easier if I'd tried to get pregnant when I was married. [Stewart divorced attorney John Cuti in 2004] But my ex and I were completely ambivalent about kids. We weren't ready.

Now, I no longer have the luxury of having doubts. A child is your legacy. What better thing can you do in life than put a really good person in the world who's going to make it a better place? And my mom's just desperate. She has wanted grandchildren forever. Forever! She's always like, "For my birthday, I would like you to be pregnant." And I'm like, "Me, too!"

My gynecologist always said, "Oh, I had my first kid at 40," so I never panicked. I actually thought it would take just a couple of months to get pregnant, and then I'd be done. But I've learned a few things that people should know. Take all these movie stars we see on magazine covers who are having babies in their 40s. If you say to a fertility doctor, "So-and-so just had twins at 45," he'll tell you bluntly, "It's not her egg." But no one says that in these articles. They don't even say, "It's an exception" or "It's very rare to have a baby in your mid-40s." Instead, everyone acts like it's normal. And that creates unrealistic expectations. I don't think a lot of women know how much their chances of having a child diminish as they age. [According to RESOLVE: The National Infertility Association, at age 30, fertility declines by 7 percent; by age 45, it declines by 87 percent.] Women also don't know that once you hit 40, a lot of fertility clinics won't even talk to you. They're, like, "Hmm, can't help you. You're too old." The first place I went to cost about $10,000 a month and came highly recommended. But, like a lot of fertility clinics, they're very worried about keeping their success rates high. When I didn't respond to the drugs after three months, they basically said, "Don't bother," and kept asking, "Why don't you use a donor egg?" Finally, I said, "You're fired."

Since December, I've been going to the New York Fertility Institute in Manhattan. The drugs cost $6,000, the doctors and in vitro fertilization procedures about $20,000 to $27,000—a month. They give me, like, eight times as many drugs than the other place did to stimulate egg production, then check me every two to four days.

I take two shots a day. Most of my friends freak out about the shots, and leave the room in tears. But if you don't look, it doesn't hurt. Twice, I've given myself shots on the street. I'm much more interested in taking my medication than in what anyone might think about me.

Once a month, I inject myself with a drug that causes me to ovulate in 36 hours. Just before the 36 hours are up, I go to the doctor's office and they put me under anesthesia and use an 18-inch needle to remove about 10 eggs. Then I go home to my apartment in Tribeca, change and get ready for my Sirius Radio show, Whatever, that I cohost with Jennifer Koppelman Hutt at 5 p.m. The doctor, meanwhile, fertilizes the eggs right away, using a technique called ICSI [intra cytoplasmic sperm injection], which involves poking a hole in each egg and shoving a sperm in to create an embryo. I'm using an anonymous donor, but not from a "genius" bank—those are creepy.

After the doctor conducts an embryo biopsy for Down syndrome and the myriad other things you might find around the three-month pregnancy mark, he says, "Eight out of 10 are not healthy" or whatever. Then, he tries to implant the healthy embryos. I've had two transfers; they haven't stuck. Last month after my egg retrieval, the clinic left a phone message saying I should call. They were going to tell me how many embryos were healthy. I never did. I could wait a week for my next appointment to find out. When it may be just another emotional blow, I sometimes don't need to know right away; knowing won't change it. If there are no healthies, I try to let it go immediately, because you can go crazy. Crazy.

But I'm not even close to stopping. I'm trying to build up a supply of healthy embryos because, ideally, I'd love to have two kids. I tell people who are 40, or even 35, if you have the money, freeze your eggs, or better yet, embryos. [Ed. note: The American Society for Reproductive Medicine says embryo freezing is very reliable, but still considers egg freezing to be experimental.] If you don't have a husband, get an anonymous donor. That way, if you never find Mr. Perfect, you have options. As for me, it doesn't hurt my body to keep trying. And if it doesn't work? I'll worry about that when the time comes.