Basal temperature tracker
Log your waking temperature and see this cycle as a simple line, with a count of readings and the latest value.
Your Trying to conceive mode.
Signals, not just a calendar
Turn on TTC mode to see predicted fertile days, log the signs that matter this cycle, and watch a confidence score that grows as you add more information. Same private app as your period, contraception, and sex logs. Right on your phone.
What you can do
Cycle timing plus the physical signs people actually use while trying.
Cervical mucus tracker
Tap dry, sticky, creamy, watery, or egg-white. Lua maps that to a fertility cue and keeps a color log for the cycle.
OPK tracker
Log ovulation predictor kit results as negative or positive, and see the last few days at a glance.
Confidence in ovulation
A percentage that shows how much support your logs give the estimate, plus a countdown to the likely day.
Fertile days on home, in plain words
TTC mode keeps your usual cycle view and adds a Trying to Conceive card. You still see where you are today, including bleeding when it is happening. Under that, Lua shows confidence in ovulation, how many days until the likely date, and the weekday so you can plan around a window, not a single hour.
Predicted high-fertility days also show up on the week strip, next to period days. The estimate is built from your recent cycles, the same way Lua already guesses your next period. It is a window, not a guarantee.
Basal temperature, without a science project
Basal body temperature (BBT) is your temperature first thing, before you get up. After ovulation it often rises a little and stays up. That shift is a useful confirmation, not a crystal ball for the day before.
In Lua you log the reading for the day. This cycle shows as a small line with a few points, plus a line of context such as how many readings you have and the latest value. Enough to spot a shift. Not a chart you have to decode before breakfast.
Mucus that maps to fertility, not jargon
Cervical mucus changes across the cycle. Dry or sticky usually means lower fertility. Creamy sits in the middle. Watery and egg-white are the stretchier types that often show up closer to ovulation.
Pick the type that matches what you notice. Lua fills a short fertility bar so dry sits toward low fertility and egg-white toward high, and it stamps that day’s color onto this cycle. You can look back at day 22, 23, 24 without opening a spreadsheet.
OPKs as a simple yes or no
Ovulation predictor kits (OPKs) look for a luteinizing hormone (LH) surge. A positive test is one of the closer in-the-moment signals that ovulation may be near. A negative test is still useful. It tells you the surge has not shown up yet.
Log negative or positive for the day. Lua keeps a short strip of the last few days so a lone positive does not get lost, and a run of negatives stays easy to scan. No need to photograph strips or score faint lines if you do not want to.
A confidence score that stays honest
Calendar math from past cycles is one input. Temperature shifts, mucus type, and OPK results are others. The confidence score is Lua’s way of saying how much of that picture you have filled in for this cycle. A low percentage early on, or when you have only cycle dates, is the honest answer. It can rise as more signs agree.
It is not a lab result and it is not a diagnosis. Lua does not promise ovulation on a given morning. It shows an estimate, how sure that estimate can reasonably be, and the logs you chose to keep. That is the point: more signal when you want it, without pretending the calendar knows more than it does.
Same app. This chapter, then the next.
You do not need a separate ovulation app. TTC mode sits next to your period tracker, sex logs, and symptoms. Nothing resets when you turn it on, and nothing is lost if you turn it off. If pregnancy begins, you can move into pregnancy mode without starting over.
Temperature, mucus, OPKs, and confidence stay on your phone. No account, no server, no ads. Lua is not a contraceptive and does not diagnose fertility issues. If conceiving is taking longer than you expected, that is a conversation with your own clinician.
One app for your cycle, contraception, fertility and pregnancy.
Private, flexible and designed to adapt with you.
Frequently asked questions
The things people ask us most.
What does Trying to Conceive mode show?
TTC mode keeps your usual cycle view and adds fertile-window estimates, likely ovulation timing, and a confidence score. You can also log basal temperature, cervical mucus, and OPK results for this cycle. It is the same private app, with extra tools for this chapter.
What fertility signs can I log?
You can log basal body temperature as a waking reading, cervical mucus as dry, sticky, creamy, watery, or egg-white, and ovulation predictor kit results as negative or positive. None of it is required. Add the signs that help you, skip the rest.
How does the ovulation confidence score work?
The score reflects how much support your logs give the ovulation estimate this cycle. Cycle timing from your history is one input. A temperature shift, fertile-type mucus, and a positive OPK can add more. A low percentage means Lua does not have much confirming signal yet. It is an honesty meter, not a lab test.
Are fertile-window estimates a guarantee?
No. Fertile days and ovulation timing are estimates from your cycle history, shown as a window rather than a single guaranteed date. Timing can shift with stress, illness, travel, or for no clear reason at all. Lua is not a contraceptive and does not diagnose fertility issues.
Is my trying-to-conceive data private?
Yes. Temperature, mucus, OPK logs, and the confidence score are written to private storage on your phone, just like everything else in Lua. There is no server, no account, and no advertising.