If you are having regular cycles every month then you are almost always ovulating, and timing sex to the very minute that you ovulate is not necessary. Here are three methods of ovulation detection.
 

Basal Body Temperature (BBT) Charting

After ovulation a hormone called progesterone rises, and this causes your body temperature to rise very slightly. To detect this rise, you should take your temperature first thing in the morning, before getting out of bed, or your readings will be inaccurate. You will need a special thermometer called a “basal body temperature thermometer” which will detect your temperature to a tenth of a degree Celsius (eg. 36.5 °C). Your temperature can be taken by mouth, rectum, axilla (arm pit) or vagina, but should be the same method every time. Your readings can then be plotted on a chart and you will notice a rise in your temperature for about a week to ten days after ovulation.
 

Ovulation Predictor Kits (OPK)

You can buy ovulation predictor kits at the drug store in the same aisle as the pregnancy tests, condoms, lubricants, etc. These kits are created to detect a hormone in your urine called luteinizing hormone (LH). This is a hormone from your brain that tells your ovary to release an egg when it is ready. It spikes briefly (approximately 24-48 hours) and then goes back to normal levels. When this hormone rises, the egg takes about 35-40 hours to release. You should start testing your urine 3-4 days before your expected ovulation (refer to Prediction Method above).
 

Cervical Mucous

This method is a little less reliable than the other methods because it is subject to interpretation. However, it is free. The cervix is the opening to the uterus and sperm must navigate through the cervix to meet the egg. As your egg gets closer to being ready to release, your estrogen levels will climb and this will change the amount and consistency of your discharge. During the first part of your cycle you may notice a small amount of sticky white discharge. As ovulation approaches this will change to a more watery, slippery consistency (similar to egg white) and this change helps sperm to get to where they need to go.
 
A word to the wise… Do not let your ovulations run your life. Be kind to yourself. If the first thought you have every morning when you wake up is to take your temperature because you are not pregnant yet, you will be starting every day on the wrong foot. Do it once or twice if you need evidence of ovulation but it is not necessary every month. If you think that you are not ovulating regularly you should consult your family doctor to start the process of figuring out why. There are many explanations, and it is a problem that is often easily remedied.