Six Months and No baby?

My husband and I have been ttc for six months now, and we have had no luck apart from one (maybe - no doctor could get me in for a beta) chemical pregnancy in our second month of trying. 
​My husband worked in very hot conditions (over 100 degrees) as a cook and I was wondering if that could be a factor with sperm development/survival? He has since left the job and works elsewhere. 
​Someone told me to give it four or so more months before seeing a specialist. Would it be productive to test his sperm/motility at this point?