What Causes Bleeding After The First Intercourse?

Hi... I had sex for the first time two days ago and I bled afterwards. Yesterday, however, I didn't bleed at all. Today, I had signs of getting my period (as it is supposed to come during this time of the month). However, the blood and brown discharge was only there in the morning and now there is no sign of blood whatsoever aside from when I pee (a hint of pink on the tissue). Could this be blood because my cherry was popped or is it my period? If it helps, I've never had a strong flow.