Does anyone know??

So I'm 6 days late for af and I've taken test but they say it's negative but I'm not gonna give up until af arrives, but my breast are hurting more and more everyday and now it's horrible!! I keep getting bad headaches and weird pains in my lower belly almost like af cramps but not constant cramps.. Well laying in bed at night I notice I get pains in my side and every night it switches sides does anyone know what this might be?? And has anyone been more than 5 days late and still had a bfp??