I had a condom left in me for almost a month?

Not good: Luckily, it appears you are doing well, but this is dangerous and puts you at risk of getting a serious infection. Be sure to assure you have no foreign bodies left inside your vagina in the future. Any d/c fever, pain-then see dr. for internal eval.

Should be fine: If you have no drainage, foul odor, painful intercourse and other wise are healthy "down there" then it should be fine. The body is remarkable at cleaning itself out. A condom certainly could have harbored many various bacteria, but it is not absorbent like a retained tampon, it should be fine. If you do get a foul smelling discharge, rash or similar, then you need a vaginal culture at the doctor