It might be that the reason your period was late/missed was because you have been so stressed out about whether you were pregnant or not. If you have had a period (and I mean a period, not just a few spots of blood) since you had unprotected sex then its unlikely you are pregnant. Take a pregnancy test now to put your mind at ease and you might find that the relief means your period comes (has always worked with me in the past
). Good luck!