kind of sad

So I have been married a month but my husband and have been together almost two year and we never use any sort of condoms or birth control during sex and we can never get pregnant. We are not really trying to get pregnant but we are not stopping either and it just sad because I have a 2 year old son from a previous relationship and I became pregnant in the first shot when I was 22 I'm 24 now. It just worries me. That my husband and I will never have a baby together.