Answers?Advice? Anything??!!

So Usually I Have A Normal Period,Im Not A Heavy Bleeder Its Fair & It Last 5 Days Every Month, But For The Last 4 Months I Literally Had The Same Package Of Pads Because I Was Just Spotting. I Didnt Pay To Much Attention To It Though.Well This Morning I Woke Up Cramping So Bad I Wanted To Cry & I Woke Up Bleeding Through My Underwear And Shorts & There Is Small Size Blood Clots.My Period Is 5 Days Early & Its Never Been Off.Anyone Know Why? Or What Could Cause This?!