Why Track Your Period?
Predict Your Cycle
Know when your next period will start and plan accordingly. Never be caught off guard again.
Identify Ovulation
Track your fertile window and ovulation date for family planning or conception.
Understand Patterns
Identify patterns in your cycle, symptoms, and mood changes over time.
Complete Privacy
Your data stays on your device. No cloud storage, no tracking, no data collection.
Period Tracker FAQ
How accurate is this period tracker?
It provides estimates based on the cycle length you select. Cycles can shift due to stress, travel, illness, postpartum changes, perimenopause, and many other factors - so treat the dates as a helpful guide, not a guarantee.
How do you calculate ovulation and the fertile window?
We estimate ovulation as about 14 days before your next period and show a fertile window around that date. Real ovulation timing varies from person to person (and month to month), so this is a rough estimate.
Can I use this as birth control?
No. Calendar-based estimates aren’t reliable contraception on their own. If you’re trying to avoid pregnancy, use a proven method and talk with a clinician about options that fit your body and goals.
What’s a “normal” cycle length?
Many people have cycles between about 21–35 days, but variation happens. If your cycles are consistently outside that range, you’re missing periods, or you have symptoms that worry you, consider checking in with a healthcare professional.
Is my data private?
Yes - calculations run locally in your browser, and bloom doesn’t require an account to use this tool.
When should I seek medical care?
If you have very heavy bleeding, severe pain, bleeding between periods, sudden major changes in your cycle, or you might be pregnant, it’s a good idea to get medical advice.
More Helpful Tools
📅Ovulation Calculator
Calculate your fertile window and ovulation date based on your cycle length.
Calculate Now👶Due Date Calculator
Find out your estimated due date and track your pregnancy progress.
Calculate NowWant More Advanced Features?
Try the bloom App
Get the full bloom experience with advanced tracking, predictions, and insights. All the privacy you love, with features that grow with you.
Quick answer
A period tracker helps you spot patterns in cycle length, symptoms, and timing over time. One month can be noisy, but 3 to 6 months of tracking gives a much clearer baseline for what is normal for your body.
What can change your result
- Cycle length can vary naturally by a few days.
- Sleep, stress, and travel can shift timing.
- Consistent tracking improves prediction quality.
When to get medical advice
- If cycle length changes dramatically for 3+ months.
- If bleeding becomes unusually heavy or painful.
- If periods stop unexpectedly and pregnancy is possible.