Early period

Na

I restarted my workout routine about 3 weeks ago after not doing it since October. (I do it 5 days a week and rest on the weekends)

My period started today, it’s a week early. Day 28 of my cycle, so I know it’s still normal range, but usually my cycle is 32 days.

Could restarting my exercising be the cause? Just curious, not worried.