Idk what's going on. 😣 fears are killing me

So I am 8 weeks pregnant with baby #1, so everything is new to me. I haven't been sick at all, just extremely tired every day and had some Breast tenderness a week or two ago. I feel great for the most part, but it's making me feel like that's not good. Last night I noticed some minor cramping on and off, but aside from that I don't have hardly any symptoms. My first OB appt is 7/15/15 and it seems so far away. I am so scared of a silent or missed miscarriage where the baby just stops growing. Makes me wonder if that's happened bc I don't feel pregnant. Any thoughts? First time pregnancy for hubby and I, and I am worried about this.