Your symptoms suggest that you may have conceived. The fact that you had unprotected intercourse
around ovulation, the pink spotting point to that. This could be an implantation
bleed. Please get a HPT immediately and see a specialist for further management. Stress can of course alter a cycle but does not usually cause the type of spotting that you are experiencing. You can also confirm/exclude pregnancy
through the blood test
. Hope you find this information helpful. Good luck.