Veganism and Anemia (TMI)

So, I've been eating a plant based diet for about a month and a half now. I've also been feeding my son a plant based diet as well. At his one year check up the doctor said he was slightly anemic and just to give him vitamins but other than that a plant based diet was perfectly fine, the doctor is actually vegetarian himself. I bought vitamins for my son and the next day something weird happened to me. I started bleeding. My period stopped a week ago so I shouldn't be bleeding like this. It's not just spotting, it's like the first or second day of a period. At first I was scared because I've had a problem with precancerous cells on my cervix in the past but I was checked in January and everything was fine. Then, I began to think that maybe it has something to do with my diet and the fact that I'm not taking a b12 vitamin or eating iron rich foods. I'm slightly anemic so I've always had problems with fatigue and what not but I was wondering if bleeding in between periods is also a sign of iron deficiency? I know that having a heavy flow definitely is. Anyway, has anyone experienced this while being an anemic on a vegan diet and not taking vitamins?