What Causes Missing Periods, Tender Breast, Nausea And Bloating?

hello i am 9 days late on my period which is very unusual. in june i started taking the ovulation sticks and on july th it registered that i was preparing for ovulation so we had sex. well, as i stated im 9 days late but i took 5 hpt and they came bk -. i have been hvn tenderness off and on in my breast, slight nausea, long naps in the day, and seriously bloating/cramping at the bottom of my tummy