Fainting and Lightheadedness

Morgan
I'm currently about 14 weeks pregnant and I've experienced lightheadness and tunnel vision often especially when standing up from sitting down. I had a bad episode of almost fainting while I was trying on wedding dresses a couple weeks ago and told my doctor about it. She just said that it sounded normal and it happens often during pregnancy.
 Well just yesterday morning while my 4 year old and I were grocery shopping I felt light headed again and just told myself to make it a quick trip and that this is a normal pregnancy symptom. As we were checking out I started to feel extremely bad and as soon as I pushed accept after I swiped my card I bent off because I had tunnel vision and told the cashier sorry but I'm 14 weeks pregnant and feel faint and then the next thing I know somebody is catching me and holding on to me then telling me to sit down and then when I awake I'm sitting on a bench that they had pushed over to me with about 7 people staring at me and luckily somebody was entertaining my 4 year old saying that I'll be alright and asking her about herself and keeping her right beside me. I told them I felt much better and they said that I need to wait because they had called the ambulance and the emt came and asked me all these questions and told me I wasn't allowed to drive home so they put my groceries in my car and drove me and my 4 year old home in my car. It was a pretty scary situation especially since my daughter didn't know what was happening and I was lucky enough to have somebody catch me. I called my doctor and the nurse said the doctor wasn't in until Tuesday but she would relay the message about what happened when she gets in. 
Has anybody has any scary fainting spells and is this normal?? I'm freaked out this will happen again and I won't be lucky enough to have somebody catch me or I'll be home alone with my 4 year old when this happens. 😖