I want one so badly

So me and my so have been together for almost 7 years now and we have never used any contraception as we discussed this and decided if it happens it happens we both got sti test and are clean but I still have not got pregnant I feel like there is something wrong with me I am too scared to go to the doctor incase I get told something I really do not want to hear he says it is not a big deal to him but I see how he is with other kids and he is g great. I get butterflies just hearing a baby cry I know I can be a great mum but as my I just not meant to have kids