I’ve been doing 15-20 miles per week for 2 months, haven’t lost a pound 
but my periods have gotten really light and last only 3 days unlike the usual 5/6. I was really freaked out initially but I realised it wasn’t a coincidence that the change coincides exactly with my new exercise pattern. I’m still worried and I’ll probably go to the doctor.
This is just bizarre all around. Has anyone experienced this? For me this isn’t even strenuous activity (and no I’m not underweight.)
I’ve still been feeling quite sedentary and was thinking of taking up yoga but I don’t know if I should go ahead with it.