Could I be pregnant?

Okay so the last time I had sex was late December and I got (what I think was) my period in January. My cycle started on January 25th and ended in the beginning of February. Come the end of February I didn't get my period, and here now it's late by 19 days. Also I recently experienced my first ever yeast infection and my nipples are sore. And I have a lot of discharge. Could I be pregnant??