Delayed periods with negative urine pregnancy tests - Online Doctor Chats

Doctor :   hi
Doctor :  
how can i help you?
User :   I am about a month late with my period. I have taken several home pregnancy tests and all have come back negitive. I however have all the classic signs of pregnancy. I am now as of today having stabbing pains in my lower back.
Doctor :  
ok
Doctor :  
i will help you in this
User :   ok
Doctor :  
sometimes the urine pregnancy tests continue to come negative
Doctor :  
even though you feel pregnant
Doctor :  
the bset way to confirm is
User :   thats what i have heard
Doctor :  
1.to do a blood test for HCG levels
User :   ok
Doctor :   it will show presence of HCG hormone, pregnancy hormone in blood
Doctor :  
2. transvaginal scan to gee the fetal pole inside uterus
Doctor :  
3. an examination by a ggynac
User :   ok.
Doctor :  
a pelvic examination combined with a abdominal exam will show ripened cervix to examiner and soft bulky uterus
Doctor :  
so please get all the three done, atleast the first two

Doctor :  
to confirm if you are really pregnant
Doctor :  
and also if cramps increase