Couldnt find hb on doppler

KP • Mama of two DD 04/14 and DS 03/16. #3 and last due 3/19

I'm 10w2d and couldnt find it this morning after about 5 min. Hoping I can hear it tomorrow or the next day. Anyone else having a hard time. I'm using a different doppler than I have in the past, this is my third baby.