I feel that newborns hardly get fever lei, only into the 5th or 6th month, then i recalled my gal start getting sick often. By then, i used the ear thermometer, cos the armpit one was hard to get the reading. Esp when she moves alot and it takes some time for the armpit thermometer to capture the reading.
Ear thermometer works well for me since then, got it for almost 2 years, still serving well. I also got the Braun one. Maybe can get the armpit one 1st, then buy the ear one when measurement gets difficult.