could I be pregnant ??

I'm new to this so don't know were to post just looking for some advice .. I had unprotected sex on Sat 14th of October ovulation was on the Monday.. iv been feeling really of this week .. backache , severe pelvic cramps yesterday , headaches etc all pms symptoms that I don't usually get .. my period is due next Wednesday.. could I be pregnant ?? ino it's early .. thanks xx