Hi,
Welcome to ehealthforum,
Occasional spotting after finishing with period is considered to be normal and could be due to expulsion of pending old oxidized blood. If it is persistent, it should not be ignored as it could suggest possibility of infective causes, hormonal changes, endometritis, PCOS, uterine fibroids/polyps, etc (it is difficult to comment on the exact cause without examining you and going ahead with further evaluation). Visit your doctor/gynecologist for further evaluation to look for the underlying cause. Treatment as appropriate (based on examination findings and investigations results) would be started to help you regulate your periods. Consider being in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle. Avoid vaginal douching, or use of harsh soap or perfumes in the area. Use loose cotton undergarments and avoid use of tight fitting clothes. If infective cause is detected, and if you are sexually active, get your partner also treated simultaneously, and avoid having intercourse while being on treatment to prevent chances of re-infection.
Take care.