As you had unprotected sex around the time of ovulation, all these symptoms are most likely due to early pregnancy
But, for confirmation, you need to get urine pregnancy test done, as you are almost 2 weeks overdue.
The pregnancy test you did previously was just immediately after missed periods, so can come negative.
the spotting most probably indicated implantation
So, get pregnancy test done and fix an appointment for USG.
Dr. Mrs. Sumeet Baheti