Dental problems...

I went to the doctor last week for a sore throat, and she said that my gums looked inflamed and I should go see a dentist. I haven't been to the dentist in probably 8-10 years (I'm 22) and I guess it shows.
The dentist said that I have to have at least 4 cavities taken care of right away, but they probably won't fix them until I'm in my second trimester. I'm 15 weeks pregnant right now.
I also read that if there is infection in your gums it can go through your body and cause problems for the fetus. I'm very worrid that I've had some infection for a while because I have had low white blood cell counts before pregnancy and maybe this is why.
What sort of damage could have been done to the fetus?
Please help me. I'm really worried now. My gums have been really bothering me ever since I went to the dentist.
Trinity.