9.5 weeks pregnant. when standing and trying to do things, heart starts racing, feel dizzy & faint. get short of breath. goes away when lay back down?

Pregnancy: Dizziness, fainting are common during pregnancy as your body is going through major changes- with increase the heart rate, increase blood that has to be pumped by the heart, blood vessels that are dilating thus decreases the blood pressure- especially if you stand up to quickly. However other things like dehydration, anemia, vasovagal are possible too. Lie down, move slowly, hydrate, and f/u w/ ob.