For us, it only took a few months for our first, which at the time I thought was a long time. Then when we were ready to start on number 2 it took over a year. It felt like forever! We tried everything, and it wasnt until (like other people have said) that we just relaxed (well, kind of gave up really trying) that we ended up pregnant! Then for number 3 (due in Feb) we werent really trying (though we werent protecting either, but no ovulation kits ect) the relaxed method, and we were pleasantly suprised again!
So the best advice is to relax, which is so hard to do when you want a baby, i know! ...and it doesnt hurt to throw those legs up after for a while too! GOOD LUCK!! It will happen!