Large armpit lump with 100.5 temp

Hello, i am 45 year old female, otherwise in good health,
2 months ago i noticed a lump in my armpit about 1 inch in diameter, no pain just rather large,
it cannot be seen by lifting my arm ( area is not raised ) , it seems to be very deep. no redness either and wasn't,
(or the area around it) , tender at all.
So what i did was i went and had a mammogram which was clear, as i wanted to rule that out straight away, found a clinic to do it for $40,
then i just left it alone as it wasnt painful ,i am looking for employment , then when i get insurance i would go and take care of it then.
BUT last night the area surrounding the lump became very painful as did my whole arm,
but still no redness and still not raised, still deep in the left armpit but closer to my breast than the exact middle of arm pit,
Last night & today i also had a fever ranging from 100.3 to 100.5,
i have been taking ibuprofen trying to get any swelling down & bring my temp down, no such luck,
( oh, have had 20 years experience as a Pharmacy Tech in Australia so know a few things about medicine )
the lump has also doubled in size.
I don't have any insurance & i am Australian married to an American ( seperated) and have been in the USA for 2 years, so i cannot get any financial help.
I started a course of antibiotics that i have, erthyromycin,  that i had brought over from Australia just in case i ever needed them,
If this is a lymph node infection will these antibiotics get rid of it ?
I am alternating between feeling very hot to teeth chattering cold, that is why i think its some sort of infection,
How can i see a Doctor here without it being really expensive ? I live in Nashville Tennesee,
do i need to see a Dr, or should i give these antibiotics a few days to see if the lump shrinks etc ?
Please let me know what you think,
Regards Jackie

[J.M. Keyes, MD]

Hi there,
Yes, the respiraory illness could certainly be causing your fever, but if you have an infection in your armpit, that could be doing it too.  
It is hard to tell exactly what is going on without examining you and feeling the lump, but if it was smaller and not sore, and now is bigger and painful, you may have a lymph node that has become infected, or some other cyst/abcess.   If this is the case, sometimes antibiotics will clear it, but erythromycin isn't generally what would be used.  Also, often infected cysts need incision and drainage to heal.
If it is not clearing over the next few days (continue ibuprofen and compresses in the meantime), or you are worsening sooner (increased fever/pain/redness) you should see a doctor despite your insurance situation.  Even if the lump goes back to what it was before, and your fever and pain clear, you should have it looked at to rule out anything more serious.

Good luck and I hope you are feeling better,

JMK MD

[kitty_007]

This morning i know have the start of a head cold, sore throat, swollen neck glands & stuffy nose , Could this have caused my temp ?