How long is my cold contagious?

I started getting sick monday. It's just a cold—slight runny nose, cough, and really sore throat. Stayed home and in bed Wednesday and Thursday. Today is Saturday and I feel slightly better than when I was getting sick on Monday. I haven't seen my boyfriend all week because we're in college midterms and I don't want him to catch it. How much longer will I probably be contagious?