STD vaginal bleeding

i had a sti before (chlamydia or gonorrhea i think) but i didn't took a professional help due to financial reasons.

what i did is research the internet with possible medications.....

i took ofloxacin tablets 400gm twice a day.

symptoms are gone within a week but continued the medication for 2 weeks.

my new girlfriend was a virgin when we first have an intercourse.

my problem is that, she is now experiencing vaginal bleeding which is now lasting over a week.

i don't think its her menstral cycle coz, her last menstral ended jan.22

but when we had our last intercourse last jan.25 she started bleeding after our sex and last still now.

i'm afraid to admit to her that i had a STI before........
i love this girl.....
and i don't want to lose her this way....

could i be still infected with a STI that i passed to her???

but what would it be???

or could it be a natural (non-disease) thing????

i really need your advice with this....