light period but pregnancy symptoms.

I'm on day 5 of af but it's been extremely light. I haven't filled up a tampon or a pad and I was spotting yesterday and the day before and today nothing. I've been having preg symptoms like headaches, horrible Nausea, veins on my breast, my breast look and feel bigger, and there's weird bumps on and around my nipples. Don't know if that's a symptom or not. I've also beeem really moody and tired. Has anyone ever had a light period and still been pregnant?