Worried sick of not being able to conceive.

I'm new to this site and just wanted some answers about what's been bugging me for a while.

I'm 19 I caught clamydia when I was 14 back in august got checked the and had it for over a year then got tested then caught it again a year later but only had it for about 2 weeks, anyway the doctor told me it could call fertility problems I didn't think much of it but when I turned 16 I started to try for a child I knew it was a low risk of having one because I was so young, so gave up trying, I've been with my partner for nearly a year, he's always got 4 children and is 11 years older than me and we are trying I'm just worried about what if I can't have my own little baby? Some nights I cry in his arms begging him to try his hardest, I went into the doctors to see if I got checked and as I've not been with this partner for a year they won't test me or him until we've been trying for just over a year, but yet I've been trying with an ex for 2 years and then nothing now with my partner now, still nothing I use the sticks to see when I'm fertile and they keep coming up with not fertile. 

When I'm late I take a pregnancy test comes back negative my periods are abit odd some times a few days late sometimes a week late and sometimes there on the right date, 

Has anyone else had this problem?:'(