My husband and I were NTNP for over a year. I wanted another baby, so did he, just put it in God's hands. Neverrrrrr knew when I was OV, didn't know about taking temps, and who would've tought to check your cervix?!? (lol) I always kept a list of dates in reguards to my period, just because I had such an irregular cycle when I was off BC (anywhere from 28-38 days). So, I figured since I was so irregular, and had NO clue about OV, it would just be luck. Well, I got pregnant, and sadly enough, miscarried at 5wks. Well... we realised... as we were leaving the hospital, and we were shattered, that it was time for another one. But, even TTC, we just had alot of sex (ALOTTTTT!!! haha)... and I GUESSED at when I 'should' be OV. Even then, it took us 7 months to get pregnant (I'm 12 wks now!).
My point is... I think as a female, your clock starts ticking (even at 25yrs old, lol). A miscarriage really puts things into perspective. I think what happens (if you've ever had one), it goes one of two ways.... you either want a baby right then and there, or you don't (at least for a longggg time).