A: I’m glad you're asking for advice. Having a baby can sometimes require professional help.

Your doctor probably informed you that ovulation (the monthly release of an egg from your ovary) occurs approximately 14 days prior to each menstruation. This means that in a 28-day menstrual cycle, an egg is released on day 14. If your cycles are irregular, predicting ovulation becomes tricky. In a 40-day cycle, ovulation occurs on day 26 (40 - 14 = 26), while ovulation occurs on day 12 in a 26-day cycle!

This information can let you know in retrospect which day ovulation occurred but doesn’t allow you to predict ovulation for a particular cycle. If you review the length of your menstrual cycles over several months you can see the range of when ovulation has taken place.

Another way to confirm ovulation is by measuring your basal body temperature. This is your body’s resting temperature early in the morning, most easily recorded with a basal body thermometer placed under your arm while you’re still in bed. (A basal body thermometer is marked in one-tenth of a degree increments and is easier to read than a traditional thermometer.) Your core temperature is lower in the first part of your menstrual cycle and rises about one degree after ovulation occurs, remaining elevated until your next menses. Another indicator of ovulation is your cervical mucus, which becomes thin, clear and stretchy around the time of ovulation.

Predicting ovulation for a given month is a bit trickier and more expensive. The easiest way to predict ovulation on your own is with a urine test that measures luteinizing hormone (LH). LH is a hormone that rises before ovulation, and an LH surge precedes ovulation by 24 to 36 hours. Several over-the-counter LH ovulation tests are available that include specific instructions. Many physicians recommend keeping a chart that records menstrual cycles, basal body temperature and frequency of sexual relations. To achieve pregnancy, it’s best to have sexual intercourse at least every other day during the most fertile days of the month.

Gynecologists typically define infertility as a couple’s inability to conceive after a full year of trying. Many doctors don’t wish to interfere with nature until a year is up, as 80% of couples will achieve a pregnancy by this time. However, when you have a health condition that can reduce your chances of natural conception, it’s reasonable to seek help sooner.

It would be good to know the cause of your irregular cycles. Thyroid imbalance and other endocrine conditions (such as polycystic ovarian syndrome) can cause menstrual cycle changes. Having irregular cycles qualifies you for a thorough evaluation and will likely include blood tests to evaluate your thyroid and ovarian function. An infertility evaluation also covers other factors related to fertility including (1) a semen analysis (40% of infertility results from male factors), (2) a tubal dye study to confirm that your fallopian tubes are open, (3) an assessment of the quality of your cervical mucus and (4) possibly an ultrasound to evaluate the appearance of your uterus and ovaries.

I think that you should have someone “coach” you through this, preferably a gynecologist with expertise in endocrinology and fertility. At the very least, you’re likely to need blood tests to ascertain if you have an underlying hormonal imbalance, and you may be offered medication that can make ovulation more regular and predictable. You can still achieve a pregnancy with irregular cycles. It just might take longer than you’d like to wait. Good luck.