Trying to conceive

Elizabeth
Hello I been with my husband for almost 7 years he a child with his previous ex.I've been trying to get pregnant for five years   I had a miscarriage about a year ago and I have two children I have never had a problem conciveing them I don't know what to do I have sex every single day sometimes twice a day. We want to have a baby together I really want to get pregnant. I'm really getting hopeless my children are big already and me and my husband desperately want a baby