About two months ago the condom slipped off while I was having sex with my boyfriend. I'm on birth control, but because I never took my pill at the same time everyday, I got worried and went and took Plan B. My period came a day and a half late and even though it lasted 4 days, it was a very dark color and the flow lighter than normal. I continued taking my birth control pills and made sure I took them around the same time everyday. My period came right on time this cycle, it started off really dark again but then it turned back to a normal red color. The flow was as heavy as normal and it lasted 4-5 days. I got it Saturday morning and it stopped Wednesday morning. However, I just got home from work a few minutes ago and after I went pee I wiped and there was some more dark blood. Is this normal? Should I be worried, or expect another period?