Hearing that a case of the stomach flu is going around at the same time you are trying to conceive can be disconcerting. Some flu symptoms are similar to pregnancy symptoms. Deciding whether to call out sick at work or buy a baby name book will be easier if you know the differences in the symptoms between the two conditions.

Upset Stomach

An upset stomach can signal both pregnancy and stomach flu. Morning sickness happens in the early weeks of pregnancy and is caused by hormone fluctuations. Morning sickness can happen at any time during the day or night. Often, morning sickness will cause you to vomit, but you can also have nausea without vomiting. Morning sickness can last several weeks, or for some women, several months.

The stomach flu can also cause nausea and vomiting. When these symptoms are caused by the stomach flu, they are typically accompanied by diarrhea and severe stomach cramping, according to the Mayo Clinic. Nausea and vomiting caused by the stomach flu typically lasts up to four days.

Tenderness

In pregnancy, your breasts may become quite tender. Putting on a bra, bending over or brushing against a breast, may produce pain that can range from mild to severe.

When soreness is due to the stomach flu, you will usually be sore all over your body. Joints, muscles and sometimes even your skin, may all become sore to the touch or from movement.

Fatigue

A classic symptom of both pregnancy and stomach flu is fatigue. In pregnancy, fatigue is caused by the sudden increase in progesterone. In addition, when you become pregnant your body experiences an increase in blood volume and a decrease in blood pressure, which can both cause fatigue.

Conversely, fatigue caused by the stomach flu is not about increased hormones. Several factors can contribute to it, including low blood sugar created from lack of eating.

Dizziness

With the changes in hormones, blood flow and blood sugar experienced in early pregnancy, dizziness is a common symptom of pregnancy. The dizziness can occur when you stand up too quickly after sitting or when you climb stairs. This symptom can take several weeks to subside.

The stomach flu can also cause you to become dizzy or lose your balance. This is caused by low blood sugar from lack of food, high fever, if you have a fever or dehydration from vomiting and not replacing fluids.

Duration

Pregnancy symptoms that resemble the stomach flu can last several weeks. The stomach flu should clear up within 72 hours, even though you may still feel weak and dehydrated for a week.