Advice please ladies :)

Cathryn • Im 24, married,have been TTC for six months.
Hubby and I are ttc for the first time. Im currently 5 days late but am getting negative test results. Ive had cramps for the last week and would usually have gotten my period at the first sign of cramps. How long should I leave it before going to the doctor for an internal exam? Im HOPING the home tests just arent right for me :)