depends on proper timing of ovulation & unprotected sex. Early pregnancy test may give false negative result. Therefore, you should do home pregnancy test after missed period. You may require blood test
or one ultrasound
scan to confirm or exclude pregnancy.
In exclusion of pregnancy, other close possibility is Pre Menstrual Syndrome (PMS) which occurs 1-2 weeks prior to commence period. Then you should follow certain measures like
1) avoid salty food/ coffee in 2nd half of period,
2) Avoid stress
by yoga/deep breathing,
3) Control body wt by regular physical exercise
4) Take healthy diet and drink lots of water
5) wear tight breast support for breast discomfort
6) use some medication like anti spasmodic for cramp
7) maintain personal hygiene and need proper sleep.
Be well and take care.