baby thermometer for seven-month-old

Hey ladies
     What type of  thermometer are you using for your babies? 
     I've been using a regular one to get a rectal temperature. But now that she's more moblie I'm having a hard time getting an accurate temperature. I know she's running a fever.  We have an appointment at 345 with her pediatrician 
  There are so many options Idk what is best