Panicking

Today I have accidentally stumbled upon a lot of scary stories in here about law term miscarriages and stillbirths and now I'm all up in a frenzy. I am 18 weeks now and had an appointment this past Monday. Dr said everything sounded good on Doppler but the heart rate was slightly lower than usual. Was between 140-145 and is usually 150-155. Any comfort would be amazing. Thank you