Whats going on with my teeth? im pregnant!?

I had a strange lump on my gum appear about a week ago, i thought it was an abscess and ive been taking anti-biotics, but about ten minutes ago, the tooth thats directly below the abscess ( or whatever it is) has snapped in half! There are still bits of the tooth wobbling and im worried i might choke on it if im asleep. I have made an appointment wth the dentist for tomorrow ( earliest i could get) But is there anyone who has any idea whats going on?