Hsg concerns

Well today I am having an hsg done for very first time I am so nervous because I am 28 years I suffer from pcos and endometriosis (talk about a double threat) it's been a problem for so long I'm glad I'm in the generation where medicine is progressing but I have a million and one thoughts running what if something else is wrong what's if I can't have children? Has anyone had this procedure done before? What advice can you give me?