Dizzy spells

De
I am still currently working but plan to quit in March. I'm a night cashier at Walmart. Lately as soon as I get to work and start checking people through my lane I get horrible dizzy. Like blackout vision dizzy. And I have to stop and sit down for quite a while before I'm okay again. I feel terrible because I know I'm putting more work on my co workers when this happens cause someone has to take over for me which delays whatever they were doing. Today it was so bad that I ended up calling my BD to come get me and went home after only being at work for less than an hour. I ate before I got to work and I take a water bottle and snacks up to the register with me also. So I don't know why this keeps happening. I do plan on bringing it up to my doctor next week, but I just know I'm going to probably end up getting fired because I call in/ leave work early so much. Any one else's pregnancy kicking their butt or am I just being a big baby?