Hi,
Welcome to ehealthforum,
Some women can have diarrhea as symptom of pregnancy. It usually occurs due to irritation of bowels as a result of growing uterus. You should however get your stools tested to rule out infective causes or any other underlying problems. Consider visiting your gynecologist/obstetrician (not GP) for further evaluation and assistance. Take adequate rest. Drink plenty of water. Maintain healthy diet.
Take care.