Heart breaking

Me and my boyfriend have been together for 3 years, 1 year of that time we have not used any protection. We are actively for a baby but nothing ever seems to happen! Now its causing stress on our relationship and we are aruing all the time! Its the only thing we talk about these days. I love this man with all my heart and really want to bring his child into this world. Im worrying that maybe there is something wrong with me and that i cant have children. This is making me depressed and i dont feel like trying for a baby as everytime i think i am pregnant i am let down and i dont think i can handle the stress! Can anyone advise me on anything i have said in this blog?? If so please message me! Your help will be hugely appreciated!!