Period late had sex today it hurt then started to bleed lightly not enough for a pad or liner is this common in a pregnancy ?

Late menses: You findings could suggest an early pregnancy, but is not necessarily common in pregnancy. I suggest that you do a home urine pregnancy test, and follow up with your gynecologist if it's positive..

Could be PG need a : Quant b-hcg blood preg test, it measures down to 5 miu could be other causes you need an exam and maybe cultures to r/o infection and blood work and an ultrasound by your gyn.