My period is due but i had sex and saw blood for a minute and it stop what's wrong?

Light period: It is fairly common for the motion of the penis against the cervix to produce a drop of blood, particarly if the cervix is irritated or inflamed, or if you are starting with a new sexual partner. At the time when you are expecting your period, it is not uncommon for intercourse to start the bleeding for this period. Alternatively, it may just be a very light period (e.g., if you are on birth contr.