Which birth control method do you suggest?

Hi I've recently began becoming more intimate wth my bf. We've always used the withdrawl method and it's been working but I'll feel better with something else. I'm a lil scared of needles and I can't swallow pills no matter how small. But I can deal with a needle occasionally. What do you think will work for me. I'm very petite (15 bmi) tell me what works for you! Thanks!