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Ovulation calculator

Find out when you’re likely to ovulate – and increase your chances of getting pregnant!

How does it work:

Enter the first day of your last period then enter how long your cycle usually lasts. We’ll determine when you’re most likely to be fertile in your current cycle.

1. Is your cycle usually regular? 1
2. When was the first day of your last period? 2
3. What is the usual number of days in your cycle? 3
3. What is the shortest cycle length you usually experience? 3
4. What is the longest cycle length you usually experience?
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  1. If the number of days between your period is always the same, or differs by one day, we consider your cycle to be regular. ↩︎
  2. The first day of your last period refers to the day on which you experienced full flow. You should not count the first day of your last period from light bleeding or spotting. ↩︎
  3. Your usual cycle includes the number of days from Day 1 of one period until Day 1 of your next period. ↩︎
  1. If the number of days between your period is always the same, or differs by one day, we consider your cycle to be regular. ↩︎
  2. The first day of your last period refers to the day on which you experienced full flow. You should not count the first day of your last period from light bleeding or spotting. ↩︎
  3. Your usual cycle includes the number of days from Day 1 of one period until Day 1 of your next period. ↩︎
  • What does the term ‘cycle’ mean?

    The term ‘cycle’ is shorthand for a woman’s menstrual cycle. A woman’s menstrual cycle refers to the hormonal and reproductive system changes that make a pregnancy possible.

  • What is the usual length of a cycle?

    A typical menstrual cycle, which begins on the first day of your period until the first day of your next period, lasts anywhere between 28 to 35 days. However, it is normal for cycle lengths to vary between women. For example, some women may have regular cycles that last around 24 days.

  • What are the different phases of my cycle?

    The two phases that make up your menstrual cycle are the follicular phase and the luteal phase.

    The follicular phase occurs from the first day of your period up until ovulation. During this phase, estrogen levels in your body increase leading to ovulation. The lining of your uterus also begins to thicken to support a possible pregnancy once your period has stopped.

    The luteal phase occurs after ovulation until the first day of your period (when the lining of your uterus sheds). It predominantly involves an increase in progesterone which supports the thickening of your uterus lining. If sperm fertilises the egg, the resultant embryo can attach to the wall of the uterus. However, if fertilisation does not occur, progesterone levels decrease and the lining of the uterus sheds.

  • How do I work out the date of my last menstrual period (LMP)?

    Day 1 of your LMP is the start date of your last period – i.e. the first day you began menstruating at full flow (ignoring spotting and light bleeding).

  • If I’m trying to fall pregnant, what is the best time to have sexual intercourse?

    Typically, a woman is most fertile 2–4 days before ovulation up until the day of ovulation itself. That’s why if you’re trying to conceive, we recommend timing sexual intercourse to occur on these dates.

  • What should I do if my cycle length isn’t regular?

    If your cycle length is irregular, we recommend seeking help from a fertility specialist. Shorter than normal cycle lengths may indicate poor egg quality, anovulation (the absence of egg release) or a short luteal phase. Other irregular cycle patterns may indicate that you are experiencing unreliable ovulation, or the timing of your ovulation is too hard to pinpoint accurately.

  • When should I ask for help?

    Women with regular cycles

    If you are under 35 years of age and having frequent and unprotected timed sexual intercourse, we recommend seeking the opinion of a fertility specialist after 12 months of trying. Your fertility specialist will be able to guide you on whether you and/or your partner would benefit from fertility testing.

    If you are over 35, we recommend seeking help if you have been trying for 6 months without success, as fertility declines with age.

    You can also see a fertility specialist any time that you are concerned about your ability to conceive.

    Women with irregular cycles

    If you are under 35 years of age and having frequent and unprotected time sexual intercourse, you should seek assistance from a fertility specialist after 4–6 months of trying. Your fertility specialist will be able to guide you on whether you and/or your partner require a formal fertility assessment to determine why you may be having difficulty conceiving.

    As your ovarian reserve (the pool of eggs left in your ovaries with reproductive potential) naturally declines with age, we recommend seeking assistance if you are 35–39 and have been trying for just 3 months. If you are over 40 years of age, we recommend contacting a fertility specialist as soon as possible.

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Get in touch

For more information or to book an appointment with one of our fertility doctors, please call (03) 8080 8933 or email [email protected]. Fertility appointments can also be booked via our online booking page.

Our three Melbourne clinics are based in Box Hill, Clayton and East Melbourne and are open Monday–Friday: 8:00am–5:00pm. We welcome patients from all over Victoria, as well as those seeking care interstate or internationally. All fertility treatment requiring day surgery or lab access (e.g. egg collection, embryo transfer) will take place at our state-of-the-art treatment centre in Box Hill. Fertility consultations and IVF cycle monitoring can be arranged at all three Melbourne clinics.

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