You won't find a heart beat on a Doppler yet
Your baby is so small right now finding it on your doppler will be too difficult. You have nothing to worry about
Its super hard for some people yo find heat beat until 12wks when uterus comes above pubic bones.
If you do try, go very low, below your underwear line and aim down.
You may not find it still. But dont panic, not uncommon to not hear at home until 12 weeks x
God bless you and your pregnancy and family