Help..

So my fiancé and I have been trying to get pregnant. We tried before he deployed to Afghanistan and when he came back. Now that he's back we've been trying and nothing. I get my period almost the same time every month. I have horrible cramps when I'm on my period. I've been tracking my periods and when I ovulate. It's just so frustrating. I feel like something is wrong with me since I haven't been able to get pregnant. Anyone in this situation? :(