Actually, condoms are good protection against pregnancy, but not the most effective form of birth control. I believe that's The Pill. I might be wrong, but condoms, when used correctly, are still a little less effective than The Pill.

However, for STDs, condoms are the most effective way of preventing them, other than abstinence.

If you're nervous about bringing up condoms to your boyfriend, scroll down on this page to where it says, "Sample Script for Safer Sex." It gives you ideas for bringing up the subject and explaining why you expect him to wear a condom. Here's a couple:

If Your Partner Says: But we've never used a condom before.
You Can Say: I don't want to take any more risks.

If Your Partner Says: Let's face it. Making love with a rubber on is like taking a shower with a raincoat on.
You Can Say: Well, doing it without a rubber is playing Russian roulette.

On that page, you'll also find a list of lubricants that are safe to use with condoms, and ones that are not. Never use an oil-based lubricant with a latex condom.

Yes, the Roman Catholic Church doesn't approve of the morning after pill (and others think it's the same as abortion, but it's not), but they also don't believe in birth control and often make rules so hospitals run by them won't provide it, even the morning after pill in cases of rape. That's my slight tangent.