Ovulation usually occurs about 14 days after your period, but if your cycle is longer or shorter than 28 days your fertile period will be later or earlier accordingly.
During your monthly cycle the body goes through various changes to prepare for getting pregnant.
The cycle is mostly controlled by the hormones oestrogen, progesterone, follicle –stimulating hormone (FSH), and luteinizing hormone (LH). A peak in LH triggers ovulation.
Your body temperature drops and then rises just before ovulation. You are fertile for one day before the temperature drops, and for one day after it remains elevated.
Your cervical secretions go through a cycle of changes too. As you approach your fertile period the secretions increase and become clearer, stretchy, and slippery ready to receive sperm for getting pregnant.
At ovulation one follicle ruptures, releases its egg, then becomes a structure called the corpus luteum. This produces the hormone progesterone, which is essential for the development of an embryo. If the egg is not fertilized, however, the corupus luteum shrinks.
After ovulation, under the influence of oestrogen and progesterone, the endometrium (lining of the uterus) becomes thick and spongy to receive the egg. If the egg isn’t fertilized, the corpus dies and the endometrium is shed at your next menstrual period.
Here is an approximate fertility guide based on a 28-day cycle to help you get pregnant. There can be a slight chance of getting pregnant throughout your cycle as men's sperm can live inside a woman for as long as seven days.
Day 1-5
Development Menstrual period
Hormone levels Normal, FSH slight increase
Body temperature Normal
Cervical Secretions Period (usually no secretions)
Day 6-9
Development Relatively infertile phase
Hormone levels Normal, Oestrogen begins to rise, FSH dips back
Body temperature Normal
Cervical Secretions Dry, no secretions
Day 10 - 12
Development Relatively Fertile
Hormone levels Oestrogen rises steadily
Body temperature Begins to drop
Cervical Secretions Moist, sticky, white, cloudy
Day 13-15
Development FERTILE
Hormone levels Strong rise in LH, FSH
Body temperature Drops and rises sharply
Cervical Secretions Wet, slippery, stretchy, clear
Follicle/ Egg Peak fertile period- the egg is released from the ovary.
Day 16-19
Development Relatively Fertile
Hormone levels LH, FSH drops back to normal, oestrogen levels out, progesterone rises
Body temperature Remains slightly higher than normal
Cervical Secretions Moist, sticky, white, cloudy
Day 20-28
Development Infertile phase
Hormone levels Oestrogen and Progesterone stay fairly high, eventually drop.
Body temperature Steadily drops back to normal
Cervical Secretions Dry, few secretions
Taken from the book: Conception, pregnancy and birth, by Miriam Stoppard. Click here for more information and to purchase.
