Period woes

Jerene
Okay, so a few of cycles back, my period was non existent and I was freaking out as my boyfriend and I have been having unprotected sex and using the pull out method. I tested using a pregnancy test twice and both times came back negative but I knew they weren't super accurate.
I read online (I know, pretty silly) that vitamin C in excess can cause uterine contractions and so I had heaps of vitamin C and sure enough it came for a few days.
Fast forward to my next cycle, it was spotty for 8 days which is very unusual for me as I generally bleed for 3-4 days. I was kind of worried I messed my body up and took another pregnancy test just for good measure, still negative.
My next cycle after that was normal.
Anyone know what the heck happened to my body? 😂