What Causes Delay In Periods, Sore Breasts And Stomach Pain?

hi i am gettin a bit worried please can you help i am 28 and ive been tryin for a baby now for nearly 5 months i allready hav 3 children i was due on my period on the 19th but i havent come on yet ive done 2 test both say negetive i have sore breasts that feel brused and my nipples are sore and tender i also keep gettin a sicky feelin now and then that last for max bout 10 mins im getin sharpe pains in my tummy every now and then i dont have a doctor as i dont have photo id i also had a few symtoms of cervical cancer and was told to go for tests but im scared even more now and dont know what to do please help me