Alicia
it could be low blood pressure as during the first 24 weeks of pregnancy it is common for low blood pressure.
Symptoms of low blood pressure to watch for include:

Dizziness or lightheadedness
Fainting (called syncope)
Lack of concentration
Blurred vision
NauseaCold, clammy, pale skin
Rapid, shallow breathing
Fatigue
Depression
Unusual thirst

Is definately needs to be checked by a dr but also check your sugar levels.
Pregnancy is full of suprises! I hope your dr finds whats going on!