First of all, you should undergo a blood test
for beta hCG or TVS scan (around 4 weeks) to confirm or exclude pregnancy
If you get negative result again, then other reasons of irregular spotting like hormonal imbalance, stress/ anxiety, ovarian cyst
, thyroid problem, wt gain/ extreme loss, irregular eating habits etc. are needed to be ruled out properly.
Here you need some investigation to rule out underlying pathology by USG pelvis,Thyroid profile, LH/ FSH, Blood estrogen & progesterone
level etc. So consult with your doctor and take suggestive measures.
Avoid stress,take healthy diet with iron supplements
,control body wt and need proper sleep.
If you need further consultation with me,then you can visit http://www.healthcaremagic.com/doctors/dr-soumen-patra/63326.