Nausea Before Period? No Blood?

Bri

My period is supposed to be coming soon (2 days according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>) and the past couple days I have been nauseous and cramping a bit, acne ( my face is usually very clear) and other stuff but no blood. I am thuroughly confused because like WHY ISNT THERE BLOOD? jusy regular discharge, also I am on the pill if that matters. Is this normal?