Thank you r850723!!! Like another poster, I had done all the "tricks" - unplug/plug, q-tip, soft reset, reset network settings, unplug/plug during call, etc. I was so worried because this phone is only 6 weeks NEW and I knew for sure there was no water damage, it was never dropped, etc. The phone was working fine yesterday then this morning I woke up to change my ringer to loud and then it said headphones only.
I did your trick exactly as you put, except the last step I hung up and then changed the ring/volume switch on the side and voila it went back to "Ringer". Thank goodness I don't have to take a trip to the Apple Store. But if it happens again unfortunately I will go into the Apple Store because it shouldn't be a recurring thing! Thanks!
1) have someone call you (I called myself from my home phone)
2) turn on to speaker mode
3)turn off the speaker
4) plug in your headphone
5) un-plug headphone
6) hang up
7) adjust the ring/silent switch
It should no longer say "headphones"