Getting pregnant

I have been trying so hard to get pregnant try at least 3 times a day for the last 12 months and I can't I have a almost 5 year old and would love to another one but I can't idk wat to do I have sex at least 4 times a week at least 3 times a day and nothing...... I had a miscarriage about almost 8 yrs ago does that affects anything at all please help.... My name is NATALI FLORES