I am 35 years old and have 2 children. I was able to get pregnant very easily in the past. I have had some spotting and have had my progestrone levels checked. They were on the low end but within normal range-whatever that means. I read about vitamin b12 and started to take it. I have totally missed my period (never has happened). I know that I am not pregnant. Could the increase in b12 caused a no show period?