Feeling frustrated

My partner and I have been trying over a year and still no luck I seem to just get the disappointment that I'm not pregnant every month it's really starting to get me down my partner is being tested this week and so nervous for the results how can I think positive in a not so great situation we are both 21 been together 4years and have recently moved into a two bed flat just waiting to make us complete with a new arrival 😢 
should I see a doctor about how down I'm feeling?