I had a full on period but the cramping and back pain was intense. and I was breaking out and super hormonal. I think anything really dramatic and unusual like that is a very good sign.

I had very light period-like cramping about a week before my period was due. I also had a day and a half of spotting (needed a panty liner, but it wasn't enough for a regular pad). No other symptoms for me.

Same with me. Period cramps and no period both times were my first sign of pregnancy.

Yup!!! It felt a lot like menstrual cramping. I also has a very pale pink spotting from implantation bleeding