passing out feeling

I'm 9 weeks and lately I've been getting gest flashes then I feel like in going to pass out but I don't actually do when it happens I'll just have to sit down and drink some water but I dont have to be doing much for it to happen like this time I was sitting on the toilet when it happened and after my body will feel really weak. has this happened to anyone before (I was supposed to go to the doctor today but they canceled the appointment becasue shes had an emergency)