No, you are not pregnant as you had sex with your boyfriend one day before you due date and as your aware of your ovulation,which usually takes place around 13th day of cycle.The abdominal cramps and burning sensation during urination all symptoms of urinary tract infection
.(UTI) which you got during sex .
You need to see a physician to get your UTI treated .
Sometimes periods can be light ,you need not to worry for that.
Hope this answers your question