thank you for asking,
Spotting and menses and alot of pain needs a bit work up. 7 to 10 days is average time for that. If you dont have excessive menses then all you need is to look out for etiology of dysmenorrhea (pain ful menses) atop of that is endometriosis
for which you need work up and which will be advised by Gynecologist., So A good expert's eye and some reassurance is all you need.