Scared to get my hopes up...

I've taken 3 positive pregnacy test and I feel pregnant, I'm going to go to the doctors within the next couple of days, went to wmart and bought some prenatal vitamins, I just don't want to get too excited I'm worried about having a miscarriage I see sooooo many posts saying that their 1st ended in miscarriage...it makes it hard to be fully excited I'm 4 weeks and 3 days .