Irregular Periods.

I haven't had a regular period since.... Ever. I got on BC when I was 16 to help them become regular and have been on BC since.. Well, until this past June. I took my implanon out and decided to stay off BC. Since then, I'll bleed every once in awhile, but it's extremely light - lasting two or three days. Yesterday and today tho... It's terrible! Extremely heavy! I don't know what could be going on. Any idea? Suggestions? Anything?!