Hi, i have this spot on my arm that turns red everytime i have my period. When my periods dpne, it fades a little and turns light black like a bruise. My doctor said it might be endometritis? 1month ago i had unprotected sex with my boyfriend, now im delayed 1 week already and the spot is red again. But still no menstruation. This is the first time it happend, that the spot is red even if i dont have my period yet. What does this mean please help.