Disappointed. HELP!

Abbie
AF was suppose to visit 7/26 but it never came so I took a test and it was negative. I'm very frustrated because I had sex in my fertile window many times and still nothing but a BFN. I haven't really had any symptoms of my period coming except my breasts hurting. I've been having some slight cramps off and on the last few days/week before this week and it just seemed like this month would have been the month, I had a strong feeling that I was pregnant and I'm not. Does anyone have any suggestions for getting pregnant next month?