I and my boyfriend had sex on 14th August and there was no ejaculation of serum in my vagina. Actually my periods should be on 24th August but there was a delay in my periods till today. Even I had my pregnancy test and it was shown negative result. Then what is the reason for delay of period? Is that because of stress or Should I wait for sometime! what is the medicine to be taken for unnatural periods? And also I have a problem like an infection in vagina I feel like itching and white discharge of fishy smell. What does that indicate? Is that harmful? Or should have a medicine for that also? If so what medicine is to be taken?