I fainted!!!

I’m 12 weeks and 4days today. Just had my ultrasound earlier this morning. Baby had a heart beat at 167. It was kicking, moving, and waving. Happiest day! But also scariest day! I was at a store earlier and I fainted😔 all I remember was telling my husband I think I’m going to faint while we were in line and right away, I was gone. When I heard seconds later, my husband and everyone around us were holding me asking if I were ok or needed an ambulance. My husband said I’m pregnant. Everything was blurry when I heard and I was sitting on the ground. My husband and some lady helped me up and walked me to a chair. They sat me down, gave me water and fanned me, with that my vision became clear right away. The lady in front of us in line said the same thing happened to her when she was pregnant. It’s just my body overheating and not pumping enough blood to my brain so my body shut down. I called my OB , he said it’s common and for me to go home, drink plenty of fluids and rest. If it happens again within 24 hrs to go to the hospital. If it doesn’t, then it’s just a common symptom and that baby and I are okay. Should I be relaxed about it or get checked up??? Has anyone fainted before???? Scariest experience ever!!!!!!