Time in between ultra sounds

So my last ultrasound was at 8 weeks and my next one is on Tuesday when I am officially 12 weeks.

I have been feeling great .. a little too good for my liking ... My really only pregnancy symptom I have had was being hungry all the time and sore boobs but as of lately I feel like those symptoms have gone away and I feel like I am not really even showing .... and all I am left with is a bad headache .

I got major anxiety today thinking what if I go on Tuesday and baby does not have a heart beat :(

How am I supposed to know hes ok between visits? Is this a popular concern? Or am I having a Mother’s intuition that something is not right?

I would really appreciate any advice for this scared mama over here 💙💙💙