There is a potential alternative explanation other than pregnancy for every symptom that may be related to a potential pregnancy. Below is a list of pregnancy symptoms followed by other factors or conditions that may be causing your symptoms.
Implantation Bleeding – Could be actual menstruation, altered menstruation, changes in birth control pill, infection, or abrasion from intercourse.
Missed Period – Could actually be excessive weight gain/loss, fatigue, hormonal problems, tension, stress, ceasing to take the birth control pill, or breast-feeding.
Swollen/Tender Breasts – Could actually be hormonal imbalance, birth control pills, impending menstruation (PMS) can also cause your breasts to be swollen or tender.
Fatigue or Being More Tired – Could also be stress, exhaustion, depression, common cold or flu, or other illnesses can also leave you feeling tired or fatigued.
Nausea or Morning Sickness – Could also be food poisoning, stress, or other stomach disorders can also cause you to feel queasy.
Lower Backaches – Could also be impending menstruation, stress, other back problems, and physical or mental strains.
Headaches – Could also be dehydration, caffeine withdrawal, impending menstruation, eye strain, or other ailments can be the source of frequent or chronic headaches.
Frequent Urination – Could also be urinary tract infection, diabetes, increasing liquid intake, or taking excessive diuretics.
Darkening of Areolas – Could also be hormonal imbalance unrelated to pregnancy or may be a leftover effect from a previous pregnancy.
Food Cravings – Could also be poor diet, lack of a certain nutrient, stress, depression, or impending menstruation.