Period is a week early?

Last week I started eating healthier. Had a couple days of diarrhea but got better (figured my body wasn't used to me not eating crap). I have felt a lot better since, more energized, and overall happy. Husband and I are trying for a baby, usually my cycles are 30-34 days. According to Glow this past week was my fertile week, but all of a sudden AF showed up a lil over a week early. This period is a lot different then my past ones over the last few years. My flow is light (usually really heavy), also haven't experienced any cramps, bloating or anything normal. Also no mood swings or ANYTHING. Could this be because I am eating healthier? Hoping someone would shed a little light.