A woman who does not have a Mahram to travel with does not have to go for Hajj or `Umrah and she is excused if she does not go. It is prohibited for her to travel for Hajj or for any other reason without a Mahram, and she has to be patient until Allah makes it easy for one of her Mahrams to travel with her.

Conclusion: you should try to have children, then if it becomes possible for you to do Hajj, then go for Hajj, but if it is not possible, then you may delay it until Allah makes that easy for you.