Is something wrong with me?!?

On august 20th 2013 found out I was 2 1/2 months pregnant my fiancé was out in ACTIVE DUTY. Then only way we could communicate was by writing old fashioned letters. So I sent him a letter saying I was pregnant then 2 weeks later I had a misscariage. He was devastated. We already have 1 son he turned 3 on January. He recently got back February 1st 2014 he left since July 22nd 2013. We've been trying to get pregnant. It doesn't work. I am active, I watch what I eat. Could it be me? Or him? Like are we not fertile anymore. (We've been trying to get pregnant since my son was 6 months old) only worked once and it went wrong? Now currently I'm having upset stomache, can't stand some food smells, breast hurt, mood swings...(too early to take test) March 8 when period ended. Help? Anyone?!