For many women, it's their breasts, not a home pregnancy test, that clue them into their pregnancy. The hormonal changes during early pregnancy can cause breasts to feel swollen, tender, tingly or heavy. Fatigue and cramping (sometimes with a small amount of spotting) are also common early pregnancy symptoms.
As the first trimester gets underway, symptoms may also include morning sickness (which can happen throughout the day), hormonal headaches, constipation (thank the increase in progesterone for that), mood swings, dizziness, and both food craving and aversions.
Symptoms vary from woman to woman and from pregnancy to pregnancy, and while some pregnancies may be symptom-free, others may have all the classics. Still others may have symptoms you don't normally associate with pregnancy, like a stuffy nose or carpal tunnel syndrome. Make a list of any symptoms that are troubling you before your first visit so you don't forget about any of them once you're in the doctor's office.