What's wrong with me ?

I'm feeling down and just need to vent, I'm so tired of this ttc, all we want is a baby and we get let down every month. I took a test this morning really really thinking it was going to be postive bc my nipples are more sensitive then they ever have been, lots of cm, mild head aches, tingly boobs/nips, tiredness, drying peeling nips, I had a pulling feeling in my right and left lower abdomen for about 2 days, they lasted around 3 minutes and I got them randomly through out the day. I just I really wanted it to be my month, my period is a day late as of yesterday which I know isn't much but I probably should have gotten a + by now if I truly was pregnant id b 4 weeks, which would show up on a test. I'm just about done. Iv tried everything. It's been 8 months now :( I know people have been trying for much longer how do you deal with it? And to make it worsen two best friends just had there SECOND babies. :((( I don't understand, I'm young, healthy, work out never had any fertility issues in my family. BOTH of my older sisters fell pregnant by ACCIDENT, and my mom has has 7 kids including me all together so, what's wrong with me :(( my fiancé and I have good jobs, our own home, TWO vehicles, and very stable. I just don't get it how all these girls who don't even want to get pregnant, gets pregnant, and I, who wants it so bad with the guy Iv been loving since I was 15 and it hasn't happened. :(