Child custody during legal seperation

What are my legal options in dealing with a stbx that is not cooperating/refusing/being difficult with me getting my children for visitations. We have been legally seperated for 2 months and every time I try to get my children for weekends or other nights there are issues or non cooperation.

You each have equal rights to the children unless there is a court order or agreement that says otherwise. I suggest you begin picking the children up from school rather than her residence, and file an action for custody.