Okay, basically my period is due in about a few days but ive been really worried as i had unprotected sex about two weeks ago (although used withdrawal), but i had cystitis about a week ago and im not sure whether this is messing with me and causing me to think i am pregnant.
My symptoms include:
Stomach cramps (this is normal before my period)
increased vaginal secretions (but with itching/burning)
increased tiredness (but i have started a new full time job and have had late nights)
lower back ache (probably related to cystitis)
I have no other symptoms which may be related to pregnancy though.

My periods occur every 5-6 weeks usually.
Is this pregnancy, cystitis, or environment change?