You will not get pregnant from oral sex. In that regard, you can take a sigh of releif.
You can only get pregnant if his sperm or ejaculate(what comes out when he "cums" touches or enters your vagina. So as long as it did not you are ok. Keep in mind though while EXTREMELY rare, some people have gotten pregnant from sperm being on someones hands and then being fingered. That would be EXTREMELY rare though.
Okay - Oral sex. I can explain this. Please don't be embarassed that you did not know and dont feel stupid! how would you know, unless someone told you or you read about it? You know? You can only know what you find out about!
Oral sex is kissing or licking of the other persons genitals. That would mean if you put your mouth on his penis, or scrotum, you would be giving him oral sex. If he were to put his mouth on your vagina, usually kissing or licking, sucking and that sort of thing, then he would be giving YOU oral sex.
You can not get pregnant from oral sex.
You can however, get STI's from oral sex. From now on if this happens, something you can do to protect yourself is to have him wear a condom, before your mouth touches him. If he is giving YOU oral sex, you can place a dental dam(sheet of plastic you can get at a drug store) over your vagina, or in a pinch, you can even use plastic wrap!
I get the feeling that you dont have a whole lot of knowledge in this area yet. Good time to gain that knowledge, i think!
http://www.sexualityandu.ca/teens/index.aspx
that is a site made specifically for teenagers, that has loads of information about everything to do with sexuality. I would HIGHLY reccomend you go over the entire site bit by bit - I think it will answer loads of questions, some you never even knew you had! lol.
Try not to be too worried about getting pregnant. From everything you have told me it sounds like you are not. However there is always that chance, so just track your period. There is really no sense in worrying until you have something to worry about for sure. If your period is late, and by late i mean give it at least a week. If that happens,THEN you will need to think about who you can trust that you can talk to that is an adult in your life.
Listen, if you want to contact me privately honey, at any time, I can try my best to guide you to the information you need and answer your questions, and if i dont know, I shall endeavor to find out for you. But please, go over that website really well ok? And if you have any questions about it, ask away! You can even post a link here if you want and ask the membership for answers if you are confused or dont understand.