Belinda,
If you were having unprotected sex, then you might be pregnant. It sounds like you may be having early pregnancy symptoms, and the spotting could be implantation bleeding. Don’t panic, but do take a pregnancy test to find out. It might be too early to tell, so if it is negative I would take another test in a week to double check. Have you told your bf that you are worried you might be pregnant? If you are not both ready to face the prospect of parenthood I would reccomend not having unprotected sex. Good luck.
Kate