Drink, drink lots of water! I had this happening at the beginning of my pregnancy.I felt beyond dizzy and felt my world around me fall. You must be dehydrated. Whenever i got like this, drinking coconut water( 7eleven has them) helps and big bottle water. Stay away from Sun, raises your dehydration, dizzy, weak, faint feeling. Oh and make yourself a pot of chicken soup blended green tomatoes. The soup helped me soo much.
Are you drinking enough? And not just water you need electrolytes too
Check your iron. I got that way even before pregnancy because I am borderline anemic