Period 8 days late, after intercourse 17 days ago. Negative HPT

My husband and I had sex on 11/1 which was 8 days after I was scheduled to ovulate as he was out of town during my ovulation. We had sex 1 day period I was due for my period after we noticed there was light pink blood and just assumed I was starting my cycle. The next few days have come and gone and no still no period. Today is day 8 with no period and I am usually right on schedule, I took a home pregnancy test this morning which showed a negative result. I have been very crampy, had increased vaginal discharge and tender breasts.Could I still be pregnant and possibly testing too early?