Sweetheart, if you aren't on birth control and are planning to consummate your relationship, it is a good idea to postpone for that reason alone. What did you plan to do to avoid making a baby?
I would wait, better safe than sorry. Besides would suggest being on the birth control for atleast a month before putting it to the test... otherwise you might end up with your first child from your first time with him. I would explain everything to him in hopes he would understand. I think he will respect you more than if you popped up with a child! Good Luck!
Don't delay your period. Postphone your first time.