You cant get pregnt by oral sex
You said he's never ejaculated? If not, then you're most likely not pregnant. There have been girls who have gotten pregnany without intercourse if the guys rubs his penis on the girls vagina, or if the guy has semen on his fingers and inserts them in to the girl.
I don't think you have anything to worry about.
I do recommend you, him, or both of you buy some condoms. Things can happen in the heat of the moment and you do not want to be unprepared.
Another thing. If you're in your teens it's not that uncommon to be late once in awhile. Stress and excessive exercise can also cause your period to be late.