LOS ANGELES — Five years ago, Lacey Murga and her husband decided they wanted to have a baby.

But Murga's menstrual cycle had always been irregular — she had a hard time figuring out the best time to try to conceive. So she looked online for ways to track her fertility and boost her chances of getting pregnant.

A quick search led her to the world of period tracking apps and wearables that help users to monitor their cycles to determine when they are most fertile. The apps, which have grown in popularity over the last several years, predict a person's chances of conception on a particular day based on individual data the user plugs in daily, such as their temperature, ovulation test results and when they started their period.

Some use the apps solely to track their cycles, or as a natural form of contraception. But particularly among people trying to conceive, many say that these apps open up a world of online friends whose cycles align, or who can provide a second set of eyes on a pregnancy test, offer encouragement and support, or commiserate when getting pregnant takes longer than expected.

"It was really helpful for me to have this community I could go to, and we're all in it together," Murga, 35, said. "With my real-life friends, I always kind of felt badly about talking about it. I didn't want to bring it up as much as it was on my mind because they hadn't gone through it."

Although many see these online communities as a way to cope with what can at times be a long journey to pregnancy, some experts worry that forums can also be a breeding ground for misinformation, whether it's vaccine disinformation or through articles with misleading, clickbait headlines.

Privacy advocates have raised concerns that after the U.S. Supreme Court ruling in Dobbs v. Jackson Women's Health Organization overturned Roe v. Wade last month, information collected by period tracking apps could become a liability if obtained by law enforcement.

The health data that people enter into most period tracking apps are not protected by the Health Insurance Portability and Accountability Act, experts say.

"Apps track you all over the place," said Cynthia Sanchez, a clinical assistant professor of nursing at USC's Suzanne Dworak-Peck School of Social Work. "I fear them sending ads claiming they can do stuff for infertility that they can't do."

Sanchez said that she tries to discourage her patients from using the apps for pregnancy prevention largely because she believes they give "a false sense of security."

"I don't think they're reliable enough," she said. "If your period is irregular you might have a hard time."

But, she added, she does support the way that apps can foster a "community of women helping each other" online.

Fertility Friend, the app that Murga uses, did not respond to a request for comment. A spokesperson for another popular cycle tracking app, Glow, said in an emailed statement that "we will continue to uncompromisingly protect our users' privacy and personal health information. Period."

"Our number one goal is to build the best products for our users and doing anything that violates their trust would go against our core values," the representative said.

Dr. Yalda Afshar, a maternal fetal medicine physician at UCLA Health, said that although she doesn't endorse a specific period tracking app, she sees them as one tool in the broader kit of fertility awareness.

"It's not a perfect science," she said of apps. "But it does empower you to make a decision that's right for you."

Tala Rezai uses several fertility apps because she likes to compare their predictions to see whether the different algorithms come up with the same conclusion. Some, she said, are more accurate than others at predicting her ovulation cycle.

The 39-year-old, who lives in Los Angeles, adds information to the apps consistently, plugging in the day on which she starts her period and the results of ovulation test strips. The apps are user-friendly, she said, and help take the guesswork out of tracking her fertile window.

"It's an overall easy process," said Rezai, who has a 4-year-old daughter.

But Rezai, a lawyer, is slightly skeptical of the community that exists in the forums.

"Are they really real? Does anybody out there really use those acronyms, or is this something the apps have decided?" she said.

The vernacular can be surprising for people coming across abbreviations such as "TTC" (trying to conceive) or "DH" (dear husband) for the first time. There are also terms like "line eyes," which people use when asking for a second opinion on a home pregnancy test, and "TWW" — the two-week waiting period between ovulation and when someone can test for pregnancy.

"If it makes [people] feel better on their journey, then go for it. But for me it's weird," Rezai said.

For Murga, it was the sense of community that kept her coming back to the app and posting in the forums, asking things like whether any potential signs of pregnancy she was experiencing were normal. She would take a photo of her ovulation tests and ask others to confirm whether they looked positive, giving her the green light to "try" with her husband. Responses to her questions helped give her the assurance she was seeking.

"When you're trying to conceive and want it so badly, you read into every sign or symptom," said Murga, who now has a 1-year-old son. "You're trying to get that support from people going through it."

At first, she was confused by the lingo people use to describe their fertility journeys.

"Someone would say 'BD' and I would have to Google, 'What does BD mean in fertility?'" said Murga. "To this day I'm like, why can't you spell it out? Why is it 'baby dance'? Just say you had sex."

For Murga, who lives in Encino, the app also created an opportunity to make friends both online and in person. She stays in touch with women in Texas, Florida and Missouri who she met because they were taking their pregnancy tests around the same time.

The conversations continued beyond comment threads, and the women felt a sense of camaraderie as they updated one another on their fertility journey — and their lives — outside of the app.

When one Florida woman she befriended visited Los Angeles, Murga made sure to have dinner with her so they could catch up in person.

Another woman, Billye Brenneisen, lived nearby and became a friend.

"It's like a modern-day pen pal," said Brenneisen, a photographer who first met Murga online in 2018. "It's so wonderful to see her dream come true in terms of motherhood. It's a super intimate journey and can be really isolating for a lot of people."

Brenneisen downloaded the app because she wanted to pinpoint when she was ovulating. The tracker, she said, helped her realize that she was ovulating later in her cycle than what was considered average and allowed her and her husband to "target our efforts."

"The whole journey trying to conceive took a while, and there were losses," the 37-year-old said. "It was tumultuous and there were the [ovulation predictor kits] and tracking symptoms and how many times you had sex and when."

Those who don't use apps track their cycles in other ways, such as writing down when they get their period each month (the analog version of recording data on a cellphone) or measuring changes in their cervical mucus.

For some, the process can be isolating, especially if it takes longer than expected to conceive or if a couple is navigating infertility. Some say that they feel there is still is a stigma attached to fertility struggles or having a miscarriage, which can make the process harder to talk about.

Fertility apps have broken down the walls that surround what can sometimes be a difficult and lonely journey to pregnancy, Brenneisen said.

"While your partner can support you, they're not actually going through it, so it was nice to have this community going through what I was," she added. "I felt like I was losing my mind every two weeks."

Brenneisen and Murga, who live about 15 minutes apart, met for the first time in person about two years ago. Murga was pregnant, and Brenneisen had her young daughter. They went for a walk in the neighborhood, stroller and dog in tow.

"We talked and it felt totally normal because it's like we had already known each other," Murga said.

"It was kind of surreal," Brenneisen added.

Although they don't see each other regularly, the pair talk a couple of times a week. They have been part of important moments in each other's lives.

Last month, Brenneisen took pictures of Murga's son for his first birthday. It was nice, the photographer said, "to see us coming around the corner with it all."