so scared I'm going to miscarriage

ok ladies I'm a mommy of two my baby girls are 9 years old and 14 months. I just found out that I'm 8 weeks a long and when my 14 month old was around 5 months we found out we were expecting but before my first dr appointment I lost the baby at 5 weeks then 3 months later we lost one at 7 weeks I'm so scared of losing this one as well . I have not talked to many people about how hurt I was or how about how scared I am. I still to this day think about the babies I lost and what I did wrong. i dont know how to not worry so much or to get over the far . we go to the dr this week and I'm hoping everything is going goo DC.