Terrified of having miscarriage

I'm 4 weeks 2 days and I know it's so early but I'm terrified of having a miscarriage! I know I shouldn't be worried but my sister-in-law just had one at 9 weeks and it's all I can think about at this point. Calling today to schedule my first appt but does anyone else feel this way? I feel like I'm just jinxing myself at this point. And does anyone know miscarriage statistics at this point in pregnancy? Is is common to have one on your first pregnancy?