My boyfriend blames and pressures me about not falling pregnant

I have been with my boyfriend for 3 years now and we have been TTC for 2 1/2 years! Recently he has been saying I'm letting him down and why can't I get pregnant but everyone else can? The gp won't refer me too a gyno and I just feel lost if there is something wrong with me? 
I fee pressured by him and he makes me feel like crap when he says its me why isn't it happening! Everyone else can but me! I'm letting him down and I just want too cry when he says it! My heart drops 
I say too him sometimes you get yourself too the doctors and look at yourself but it goes over his head as he has got his ex pregnant! 
I just feel like a let down and I am desperate for out family! I just need advice honeys 😘