Fertility issues can also influence whether a woman knows she's pregnant.
Infertility can be a painful reality for couples that want children. But the ability to get pregnant may change over time. Women who are told that they or their partners are infertile may not consider pregnancy an option. Because of this, they are less likely to notice the first signs of pregnancy.
On the other hand, some couples want to eliminate the chance of becoming pregnant through surgical procedures such as vasectomies and tubal ligation. In rare cases, a man's vasectomy may not be entirely successful. For one, it may take longer than the couple realizes for the remaining live sperm to be discharged from the body after surgery. Also, if the man's two severed sperm ducts reconnect while healing, he can still produce live sperm [source: Haldar et al.]. Assuming their partners can no longer produce live sperm during intercourse, women may not use other contraceptive methods, which could lead to an unplanned pregnancy.
Even thinking you've already experienced menopause can get in the way of realizing you're pregnant. Both pregnancy and menopause have powerful hormonal impacts on the body, and sometimes, the two conditions share similar symptoms.
Where does mental health fit in? We'll explore this question next.