1 week +/-frm due date is quite acceptable..please dont take OTC drugs since menstruation is a quite complex physiological process it depends of lots of factor,hormonal, physiological psychological like stress n so on as long as u dnt hv high amount bleed n extreme discomfort dont mess up with dis ..
Next Steps
get a hemogram done
a
thyroid function test
decrease weight if ur overweight
c a gynecologist if bleedin is too much