Welcome to HCM.
You got period 3 days earlier with light spotting type and lasted for 3 days.Also get negative pregnancy
You can confirm or exclude pregnancy by doing a blood test
for hcg.Consult with your doctor accordingly.
It may be due to hormonal
imbalance,psychological upset,wt loss,stress,mood swing
Do regular deep breathing and yoga to avoid stress and anxiety.Take healthy diet.