Cyst on chest

Angela
I have an appointment on Wednesday with a dermatologist, but I was curious if anyone else had ever dealt with this. 
I've had a small cyst between my breasts for years. It never grew or was painful so they said it was ok to leave (as recently as September 2015). In the last week it has gotten really red and looks like it's infected. Can this infection spread to the baby? Much like a tooth abscess? Do you think I need to try to get in earlier? I've read how hormones can cause changes in these, but never says anything about pregnancy or the effects on baby. 
Thank you!!