Hello and I hope I can help you today. Anyone having unprotected sex is at risk for pregnancy, however the spotting you had may not be because you conceived. Sometimes women experience bleeding in early pregnancy but that usually happens later. Whether bleeding can be caused by implantation is controversial... there are no scientific studies that proves that it occurs. But in terms of timing, it is a bit early to ovulate before day 11 of your cycle, unless they are usually less than 28 days apart. So the bleeding can be from something else, like chafing inside from intercourse, or an abrasion to your cervix. So I suggest you wait until the typical time of your menses and if you are late, do a pregnancy test. Please do not do the test before you miss a period, the results can be misleading. I hope I adequately answered your question today and that my advice was helpful. Best wishes, Dr. Brown