I Have Experienced An Early Period For The First Time.

I have experienced an early period for the first time. I am thirty three years old. I just arrived in US Oct. 16th from Hong Kong. My husband is US Citizen. I was still on my period on Oct, 16, 2016 when I arrived. I am not pregnant [just took a test] and the blood does not look the same and is not quite as heavy but is still a lot and keeps flowing. Please advise... Also, slight pain in lower abdominal area.... Thank you.