I'm in your situation right now. My ex refuses to allow me to have any extra time outside of the court order. I get to see my son 4 days out of the month. The only advice I can give is to keep asking for more time, document everything (when she allows you time and when she doesnt) do this for a year, and then take her back to court.

The judge is going to want to see that you are trying to have an active, and consistent role in your childs life. If he sees that you are asking weekly for time, and are being denied that would possibly help you out.

Good luck.