AT HOME DOPPLER QUESTION

I’m 33 Weeks. Used my Doppler today. Baby usually has a HR in high 130’s-140’s. Today it went from 130,118,145...basically all over the place. Checked again. Went from 120’s to 160’s. This was me not moving the Doppler at all. I’m freaking out. Help?! Is this normal? Called my dr and she said it was normal if I’m feeling him move but I’m so concerned.