Trying for 8months now when should I seek help?

I am 32years old and have 3 children who are 14,12,10 years old. My partner of 7years and I have decided to try for a baby as he doesnt have any of his own. I got my iud removed 8months ago and we have been trying since with no luck at all.. Should I be concerned now that somthing may be wrong? With my older kids we wernt trying or avoiding and they happened alot faster but I was alot younger. Has anyone tried for this kind of time frame and then it's just happened naturally eventually? Thanks ladies.