If you are having a hard time talking about this, it may help to say that. For example, say “This isn’t easy for me to talk about, but it’s something I’ve been thinking about a lot.”

Find a time when you have time to talk privately and there are not other things going on (e.g. not right before an organic chemistry final exam or just as your partner is falling asleep).

Don’t hold back.  Let your partner know how you feel.  The only way he or she can know what you are thinking is if you tell them.

Give your partner a chance to let you know how he or she feels.  You may find you are closer to same place than you thought. 

Respect your partner’s attitudes, values, and feelings about sex even though they may be different from yours.

Trust your instincts. If you feel unsafe or coerced into doing or saying something, stop and remove yourself from the situation.

In the end, what you do is your decision.  If you are not ready for sex, then say so.  If your partner cares about you, he or she will respect your decision.