Miscarriage with no signs??

Can you have a miscarriage with no lead up signs. I had my first apt and ultrasound at 6w1d and everything looked perfect saw heart beat and measured exactly on date by my last period. I haven't had a single spot or real cramp and I'm 7w6d today. We were thinking of telling my 7 year old daughter next weekend but I'm so scared to tell her and something happen, I don't think I could handle her broken heart along with mine but really don't want to wait till my next apt because I want her to go with me! Am I being a crazy emotional worried mom?