Hello! I know there have been a couple of older threads on this, but just wanted to start a new one - has anyone here experience mid cycle spotting (lasting more than a week) after starting pregnacare before conception vitamins? I noticed that the vitamins contain L-arginine, which increases nitric oxide levels, and increases blood flow. I am not sure if this has any indirect correlation with spotting in some individuals, but I'd be interested in hearing people's thoughts and experiences? Please advise!!
An interesting article - academic.oup.com/humrep/article/20/1/302/671492
Seems to suggest that increased nitric oxide levels might cause progestin induced bleeding?
I'm no doctor- but would like to hear people's experiences. 
Thanks