Switch to vegan affecting menstrual cycle?

Hello,

I was a vegetarian for 2 years and switched to full vegan in March (so 6 months ago). My cycles were always longer than normal (35-40 days) but then my July period was extra extra light, I missed August and now I’ve just started my period again and it’s really light again. My gynecologist confirmed I’m not pregnant and I wonder if it’s my body adjusting to no longer eating so much dairy and the associated mammal hormones that come with it. Did anyone ever experience something similar?