Alice Evans has told of her "traumatic and expensive" journey to motherhood after she and husband Ioan Gruffudd delayed starting a family.
The British actors are now parents to daughters Ella, six, and Elsie, three, after turning to IVF, but after experiencing the heartache of infertility Evans is urging other women not to wait too long to have children.
Writing in The Daily Mail, the actress said: "The fact is that Ioan and I left it late - very late - to start our family. And the worst thing is, it was deliberate.
"Looking back I ask myself how could we have been so complacent about the simple facts of life. But that's what they say: 'When you make plans, God laughs'.
"So we found ourselves playing a traumatic and expensive IVF lottery game that we were lucky to win."
The actress told how she started trying for a baby at 37, having delayed it until then so that she could concentrate on travelling and her acting career.
She said: "We were delusional about a woman's dwindling chances of getting pregnant after 35. That's not anti-feminist, by the way - it's just the plain truth.
"The whole of my 38th year was spent reading studies about fertility, taking my morning temperature, planning ovulation graphs, standing on my head after sex, and fastidiously avoiding tea, coffee, alcohol, pineapple pizza and anything else I'd read about that might possibly prevent pregnancy.
"Each month I excitedly ran to the bathroom at least five days before my period was due with a white stick in hand, and waited, my heart beating practically out of my chest for that second little red line to come up. And each month it didn't."
Evans and Gruffudd, 42, were told that IVF would cost upwards of £7,000 and that they had around a 20% chance of success.
The actress, 44, said: "Adopting was more expensive and even less likely to succeed than IVF. So there we were - £7,000 and a 20% chance of winning. Take it or leave it. We took it. And we won.
"Seeing a faint red line one Saturday morning after I'd decided in my head the IVF cycle had clearly not worked was one of the most breathtaking moments of my entire life."
Daughter Ella arrived in 2009, and the actress realised that having a baby was "the thing I should have done years ago. The only thing".
"It was as close to being in heaven as I'd ever get," she said.
The couple waited a year to try for a sibling but this time they were not so lucky, and had to go through several cycles of IVF before daughter Elsie arrived in 2013.
Evans said: "I know how lucky I am. I won the lottery. I get to kiss goodnight to the two most precious human beings I've ever met.
"My goal now is to get the word out. Don't wait until it's too late."