worried pregi

That happenes to me recently lang. I have a doppler at home. First good 30 seconds nung chineck ko ang hearbeat, irs was 109 So na praning na ako. But then nag pick up biglang ung heartbeat and biglang bumilis. Bunalik sa 155. So I asked my OB about it, she said na depende sa activities ng baby. But that is normal and that happens daw talagan