Ex no show child?

If you have a court order file a motion for contempt. If no court order, get one for visitation quickly, then you can easily enforce your visitation rights. It might be a good idea to call the local sheriff and have a "well" check done on the child to see if everything is OK. It will also let the mother/father know that you are concerned about the child and will also let her know that you are noting for the record, a missed visitation.