Weightloss delaying period ?

Recently started a weightloss journey and I have a period that last around 10 days.!According to glow I’m 6 days late. I’ve been tracking my period for a year now and I’ve only been late once by like 2 days. Is there anyway me being more active or eating a healthier diet is delaying my period? I mean I’ve only lost 6lbs and I’ve tested all bfn TIA!