Bleeding inbetween my period

Hi im a bit worried because ive had my last period normal, and i was thinking i might be pregnant because my period is a little late but ive had bleeding inbetween my period twice, once after sex, and yesterday at night i thought i was starting my period the normal flow of blood and a through the night it must of stopped and i havent had anymore bleeding.

I know i need to go to the doctor, but its just reassuring to here if people have ever experienced this, ive never bled in between periods before so im worried.

Thanks