Why Am I So Scared?!

I need encouragement. I am still terrified I am going to miscarry. I had an ultrasound at 8 weeks and baby measured exactly on time and had a heartbeat of 164 bpm. Then I went to the doctor at 11 weeks. No ultrasound, but they listened with a Doppler and found the baby easily. Heartbeat was 171 bpm. I’m almost 12 weeks now. I should not be worrying right?!