Im afraid I can't get pregnant

Ok me & my boyfriend moved in together June , we have been together since Feb 2016.. Ever since we moved in together we have been trying to have a baby. I brought Prenatal vitamins , i read online it helps with trying to conceive... Also He cums in me every single time we have sex , no matter what. But somehow i have not got pregnant, I tracked my ovulation & i tracked when I am fertile, we have had sex everytime. One day i had slimmery discharge out of my vagina & thought i coulda been pregnant, I told him & he did research online ... We were very excited but about 3 days later I came on my period & it was a real cycle , I thought I would've been pregnant , I was hoping I was Pregnant. So when I came off we been having sex everyday & he comes in me EVERY SINGLE DAY, But i still dont know if i'm pregnant, I dont think I can get pregnant, I have a doctors appointment on Friday & i will ask for a hormone test, because i really really want a baby . . but what if i cant have kids :( i am panicking & dont want this to be true. WHAT SHOULD I DOOOO!!! :(