Your nervousness is a sign of intelligence. The fact that you are debating about this issue before acting upon it shows me that you are rational & mature. I happen to be 31 yrs old & married. I've been taking oral contraceptives for over 11 years, & I can tell you from experience that even I'm worried about getting pregnant. With the nation's economic downturn, I thinks it's best to wait a little while longer before trying to conceive. (For me, anyway)
Having said this, I believe that you're on the right track in life. Just remember... "when in doubt, do without..." Meaning, don't have sex until you're 100% ready. You'll know when the time is right...