Thanks for writing to HCM
You may be pregnant as you had unprotected sex during fertile days.
It should be confirmed by urine pregnancy
test.Two vertical lines on card confirms pregnancy.Ultrasound
of pelvis can be done as it is the investigation of choice.
If pregnancy is ruled out then bowel infection need to be investigated. Symptoms may be due to bowel infection also.
You should take plenty of fluids.
You can take opinion from physician.
Get well soon.