What Causes An Armpit Swelling With Pus?

Hello doctor, myself Mrs.Teena.I have got a painful swelling in my armpit.Now it has been broken and fuzz coming out.I need to know the reason behind this.One month back i was hospitalized due to swelling in labia(vagina) and was given augmentin there.tht time i got the swelling in the labia (same place) for the third time.They send the fuzz for culturing and detected e-coli in the fuzz.Now will you help me out in finding out the reason behind the swelling in my armpit.All these happened after my marriage.Its going to be one year that i got married.