Increasing I've been hearing of people using Ovulation Predictor Kits (OPKs) to help them get pregnant. It makes sense right? When you are ready you are ready and you don't want to wait! But it seems their use could be problematic.
What are OPKs?
There are two types of OPKs available. One is a mini microscope that is reusable. I found one for $38.99 on the Chemist Warehouse website just to give you an idea of price. It allows you to look at a dried sample of your saliva. If your oestrogen levels are high, your saliva will dry in a fern pattern. High oestrogen levels accompany ovulation. If you are trying for a while, or use it for multiple pregnancies, you could save a lot of money using this type.
The other type is similar to a home pregnancy test and are not reusable. I found the Chemist Direct website offering 7 OPKs + 1 pregnancy test for $19.95 so they aren't cheap especially if you are trying for a while. Though I have heard though you can get them for cheaper and in bulk through some websites - so if you do buy them you might want to investigate this option. These OPKs detect a surge in Luteinizing Hormone (LH). This LH surge causes the egg to be released so it is also used as a predictor for ovulation.
All OPKs are just a predictor - they don't tell you if an egg was actually released.
Problems with using OPKs
I've come across a few articles on the Internet which point out problems with using OPKs. According to this website, OPKs don’t test for actual ovulation and nor do they test for when the cervical mucus is conducive to fertilization. And for some women (over 40 or on fertility drugs) they aren't as reliable. Another website says that you may gear up for ovulation multiple times before it happens. If you take just the first indication using OPKs, you may miss the actual ovulation as you assumed the window of opportunity had closed.
So if you rely solely on OPKs, you could be missing out on opportunities to conceive or even miss the right time. Charting where you rely on both the characteristics of the cervical mucus and the basal body temperature will give you much more information about what is happening,. But used in conjunction with charting your cycle, they could help increase your knowledge of your cycle and help back up your conclusions.
Some Further Reading
An OPK maker's FAQ page - good for some nitty gritty details about strip OPKs