Dizziness/fainting

Had a scare today. In the middle of getting my hair done I started feeling really really HOT. Then I started sweating, suddenly I feel myself slowly wanting to pass out. My ears started ringing and my vision went blurry. Idk what the heck happened! Was my blood pressure low or something? I’m 13w 4d, I see my OB Monday and I’m going to tell her what happened. Has this happened to anyone?