8 days late.

It's unbelievable how frustrating TTC is. I always thought it would just happen, that I wouldn't have to try so hard. Well I'm 8 days late for my period and I have had very sharp pains in my stomach but it doesn't feel like period cramps. I have had nausea and I sleep all the time. I pee constantly and I have had diarrhea. I have tested twice already and got negatives. Should I wait longer and test again? I have no signs of my period. I'm usually very on time with glow. If glow says I'm suppose to start on a certain day I always have, expect this time.