25 weeks and hr 120??? w babyboy

Yesenia
My ob always has a hard time finding baby's hb probably cause I'm overweight. She stayed on the heartbeat longer than usual counting... It was 120. I told her his movements at 24 weeks have been less but I'm still feeling him. She said he's still pretty small as long as your still feeling movements it's fine. Should I be concerned? His heart rate is usually 140's