First time Mom question

So this is my first pregnancy. I went to the Dr and had a ultrasound last week and they said everything was looking great. Baby had a nice high bpm of 161, it's where it needs to be, and everything looks good. Now has anyone had that happen and still miscarry? I'm just worried/nervous and still am afraid to be excited. I haven't had an miscarriage symptoms but, just looking for some advice!