No matter how convincing it appears, spotting is not a sign of pregnancy. If there was a previously confirmed pregnancy, spotting could mean a possible, oncoming miscarriage (not always). In your case, it could mean anything. Early spotting normally occurs during ovulation(in the middle of the cycle). Spotting after sex should be taken seriously because it may be result of some changes on the uterus’s cervix. You can go immediately to your gynecologist to find out what is going on.