Hi Everyone, I am a first time poster--we have a 5 1/2 month old female named Katie, need I say how sweet and cute she is

I do have a question for everyone, the breeder is out of town and I do not think it requires a vet call--Katie's ears have been standing since we brought her home at 14 weeks, the last few days one ear is flopping over--Cause for concern? Any and all input would be wounderful---I have searched the web and and have gotten every answer under the sun. Thank you in advance. I am driving my husband crazy asking him if he thinks it is OK