Anak, this is something na kailangan talaga ng doctor to check properly, please don't wait, schedule an ultrasound with your OB agad or go to the nearest hospital if you're worried. Sa ganitong early stage, ang heart rate readings ay sensitive at dependent sa equipment at timing, kaya dapat sila ang mag-assess ng baby mo. Wag mag-alala muna, maraming times ito ay normal lang or equipment issue, pero seryoso talaga need mo ng professional check. Rooting for you!