My temporary dental filling started to come off from sides.Can i get infection? ?

One of my molars requires root c therapy.But dentist first tried putting a medicated temporary filling to see if it would heal. It didnt.(Temp filling was good for 3 mth ony.Many more months ped and i didnt see the dentist for root c therapy due to money matters.Now the temp filling is falling off from two edges , resulting in two little holes on two ends.(so toothpick can go deep inside) When i remove stuff that goes inside with toothpick, sometimes it touchs nerves i think (based on the kind of pain) What can happen if i continue neglecting? I am also 6 mth pregnant.thanks