Passed out at work today 😳

I had eaten breakfast (bagel and orange juice) right before my shift, about 20 minutes into my shift I was assisting a patient with a flu shot and all of a sudden got extremely dizzy to the point I could barely see (which has happened twice before during this pregnancy), I excused myself and stumbled to a chair and lost conscious for about 45 seconds, when I awoke I was drenched in sweat like I had just run a marathon, my shirt was completely soaked and I couldn’t catch my breath, I called my OB immediately after, I have an appointment tomorrow morning to run some tests, the baby is moving around as normal, any one else experience this ever?! This is my 3rd baby and I’ve never had anything thing like this happen before.