Dear Gabriela,
Confession will not excommunicate you; it will free you from excommunication. It’s the abortion itself that automatically excommnunicates the person. You have nothing to fear from Confession. The priest will be only too happy to absolve you.
The Lord never turns away a repentant soul.
There is good reason to hope that you will see your child in heaven, You are in our prayers.
Fr. Vincent Serpa, O.P.