Two week what?

The worst part in trying to conceive! I am so positive at the beginning of every month, knowing it's a fresh start, with a chance to fall pregnant! Then, as the date for AF gets closer, I start to get discouraged, and then when she does show, I get depressed and want to cry and run away. I know I'm not the only one that feels this way, but I've never been pregnant and because of that I don't know that I CAN get pregnant. I wish I at least knew that it could happen and it's just a waiting game until it does.