Each case of infertility is different from the other. Hence it is extremely crucial, to be honest with your doctor about all your symptoms and problems. The doctor needs to know all the details regarding your reproductive health including any previous miscarriages, or abortions if any. This helps in diagnosis and formulating a correct treatment for infertility.
Most women over 40 who try to get pregnant will have difficulty, and fertility over age 44 is rare - even in women who are ovulating regularly every month. The point is that the older the female partner, the more likely that there is an egg related issue causing the fertility problem. Unfortunately, there is currently no specific test for "egg quality".
Impaired sperm production or function. Below-average sperm concentration, weak movement of sperm (poor mobility), or abnormalities in sperm size and shape can make it difficult for sperm to fertilize an egg. If semen abnormalities are found, your partner might need to see a specialist to determine if there are correctable problems or underlying health concerns. 

After your body releases an egg, the hormone progesterone kicks in to build and maintain the lining of the uterus. It makes your body temperature go up slightly. So taking your temperature with a basal thermometer every morning before you get out of bed can help you figure out if you ovulated. You can buy these thermometers at the drugstore. They're inexpensive, but they aren't as accurate as other ways of tracking ovulation.
The percentage of cycles cancelled between egg retrieval and embryo transfer is an indication of failed fertilization. This figure is halved with ICSI as compared to conventional IVF, indicating that it can indeed improve fertilization when the sperm is at fault. However, there are no differences in pregnancy, miscarriage or live birth rates between conventional IVF and ICSI, indicating overall similar success rates1.
Sometimes problems getting pregnant for a second or subsequent time are related to a complication that occurred in a prior pregnancy or prior to delivery (damage to the uterus, for instance). But most often, secondary infertility is caused by the same factors that would cause primary infertility — issues like advanced age, obesity, ovulation problems and so on.
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