when should i see a fetility dr

Mary • 37 yrs old and just gave birth to my rainbow baby 2/22/17 after having had 6 losses and I'm expecting again on 2/9/18
i'm 35, married in november and my husband and i are ttc. so far we've had no luck. i've had 8 pregnancies. four were misscarriages(the last one in 09) and he has two kids so we know we can make babies. How much longer should we ttc on our own before seeing a dr about this?