I was a week late due to stress and then had unprotected sex. i am now 15 days late. could i have conceived when already late?

Late for period: Stress can delay ovulation, which delays the expected period. If you are now fifteen days late, and your cycles are usually 28-30 days apart, you may have conceived since ovulation may have occurred late and when you had unprotected sex. Obtain a serum HCG test and see your healthcare provider if positive.

Yes It is possible: period being late can indicate irregular ovulation and so knowing when you ovulated is more difficult to pinpoint -with this and unprotected sex it is possible to get pregnant - a urine pregnancy test will help answer your question