What Causes Delayed Periods With Cramps And White Discharge?

I had unprotected sex with my partner and for about a week after had sharp pains/cramps in my abdomen. I missed my period in December and had 3 negative hpts and 1 negative blood test, I did have my period in January and now im a week late again. I have slight cramps followed by white discharge on and off for the last few weeks . Whats wrong?