Pregnant & foul smelling discharge.. TMI

Earlier this year (Before I got pregnant) I noticed I started having more discharge than normal, not only was it white and chunky but it smelled foul- like very strong ammonia. Of course I went to my doctor straight away. She tested me for everything possible ( any sort of infection and all STI's ) and everything came back normal and my doctor told me what I was experiencing was normal. This was probably around 6 months ago, I am now 14 weeks pregnant and still having this issue. I am having lots of discharge accompanied by this very strong smell. I am worried, but because I got no answers last time I am unsure whether going back to my doctor will be useful. Please help ladies, I am worried that whatever it is could affect my pregnancy ( although it hasn't so far) any advice?