I am 4 days late on my period. I am normally not super regular but, I am not normally 4 days late either. I just stopped a weeks worth of antibiotics for a UTI . Can this effect my cycle? I had unprotected sex with my husband 2 weeks ago friday. He pulled out. I have period like symptoms, tender breasts, tired, eating everything is site. I am also breaking out ALOT, which is not normal for me.