Starting Over

Lori • I`m the Mommy to 2 great kids & 2 awesome step kids. My fiancé & I are now trying for our 1st child together.
I am 33 with 15 & 13 year olds & my fiancé is 36 with 11 & 9 year olds..... We are now wanting to have our 1st child together (we've been together for 5 years now). 
Any thoughts, concerns or encouragements?!