I think you should contact your doctor.

Gatorade has negligible potassium in it. Only 30mg per 8oz. It is pure sugar, and you may be having gestational diabetes. Most doctors check for it anyway. Compared to some foods that have 400-800mg/serving. A can of V8 juice has 800mg or so.

Find something else to drink, please!

Your heart can race when your blood pressure falls. This is to increase blood flow to the body. It is a reflex and common.

Some pregnant women really get low in magnesium as well. Muscle tightness and spasms/cramping can signal that you need magnesium. 3oz of almonds have 270mg of magnesium. Try to each magnesium rich foods (beans are also good sources). Avoid MSG in foods...this can over stimulate nerves...monosodium glutamate is a neurological excitotoxin, and the blocker for this is magnesium.