Frustrated!

I'm 19 and my husband and I have been trying to concieve for almost a year. I'm becoming really frustrated and annoyed. I know tons of girls my age and younger who have gotten pregnant by one night stands. What's wrong with me??! I'm expecting AF any day now and I'm hoping it doesn't come although I can feel the cramps already. I'm just upset and needed to vent a little. I know it's discouraging to my husband too. It's hard to stay postibe after trying so long. Ugh ):