ttc and I need help

so hubs and I have been ttc for a few years now....we have been together for 4 years...married less than a year....I have a 10yr old daughter and he has a 10yr old son....I'm 31 he will be 39 April....we have tried preseed....Opks....still nothing....I had a very early miscarriage in July of last year.....both of us were devastated....I know I'm able to get pregnant and he's obviously able to make babies.....what can we do to help along the way?......10 years is a long time....the only thing I can remember doing different is having external stimulation while having sex....could that be the issue?