Hard time getting pregnant

So I work in a high stress job so I makes getting pregnant hard yet women around me are getting pregnant but I haven't gotten pregnant and we have tried. We stopped using protection and have tried to track my ovulation but everytime it say low chance, what does this mean? I got my period yet, I have been nauseous in the morning and sometimes in the afternoon, I've had some cramping here and there, I've been tired alot lately, I wake up and want to eat my favorite chips alot lately and I've never been one to wake up in the middle of the night so why I am I experiencing these things when I got my period already. Any tips on getting pregnant