As long as you are enjoying the sensations, is all that really matters. A small percentage of women never orgasm. As you become more comfortable about yourself and learn about yourself, it may just happen when you are least expecting it! But, from experience, I can just about guarantee that if you keep thinking about it during lovemaking, it probably won't happen. Just focus on the sensations at the moment.
For many women, oral is the only way they orgasm. While I do not encourage you to do anything you are not comfortable with, I will encourage you to keep an open mind. Perhaps someday you will be more interested in receiving oral sex. (On a side note....the vagina is supposedly cleaner than the human mouth..

). What is it that scares you about oral? Are you afraid he is going to be turned off? Or that maybe he is seeing more that he typically does? Or something else? Heck, maybe you really cannot put words to your fears, and I understand that too.
Have you ever tried pleasing yourself? Many women had their first orgasms while masturbating. As taboo as this subject sometimes is, it is a very natural way to discover your own sexuality.
So in short, enjoy the sensations, keep the idea of oral as a future possibility, and play with your self! Ha Ha. Just my two cents.