I'd go with the one hour rule on that. 5 minutes apart for 1 hour. Then contact the labor ward letting them know you'll be on your way soon. I plan on going for 4-5 minutes apart before going in. Good luck hun, hopefully this is it for you and it does sound very promising.
Also, about the intensity. I read over and over again how women contract differently and the pain is all over the place and not any two women are the same. There are just generalized feelings on how much they should hurt, etc... So go with the timing that you are. That is the best indicator imo.