Unprotected sex, missed period by a week, but now bleeding?

[Emily W]

Could I still be pregnant?
I took a couple of HPTs, which were negative
but possibly too early to tell
Had unprotected sex all last month
but yesterday, i began with brown discharge
and now full on bleeding like a period

could I still be pregnant?
and if you've been pregnant before
and didn't bleed through pregnancy
could it happen this time even if it didnt last time?

Thanks