Passing out during pregnancy

In my first trimester I would feel very faint and dizzy I was working a job I was able to sit down for a lot of. Now i am in my second trimester. Today was my first day as a Hostess. I passed out an hour after being there. I started to feel hot and dizzy and said I was going to go to the bathroom, next thing I’m on the floor don’t remember it. I am tired of coming to the hospital and the doctors and them telling me it’s normal in pregnancy. Sure maybe it is, but what is causing this for me. I feel like I am not able to work because when I do I pass out or have to sit down before I do.

And before I get the normal responses: yes I am eating, yes I am drinking enough fluids, taking prenatal vitamins. Everytime I get my blood pressure taken it is normal