I had unprotected sex on the 16th, and on the 21st I got what looked to be a period, it was pretty heavy, but I had no cramps just stomach pain. This "period" stopped on the 24th then came back lightly. Now it's the 26 and nothing. I've been nervous because it was my first time. I don't have tender breasts, and I don't really get hungry. I can't be pregnant - I'm not ready.