I Started To Do Heated Yoga Last Month And Lost

I started to do heated yoga last month and lost around 10 pounds. I missed my period by two weeks right now, last last week I started to have some light spotting in the mornings only. The spotting and a little blood in the morning continued for a week now. I took a pregnancy test today and I am not pregnant. I lost a lot of weight before and while my period last late before as long as a month, I never had spotting in the mornings. Should I go to the doctor or is it just s lifestyle change effects?