I went on my period on the 21came back on 8th and its heavy and I have huge clots and its been 3 days and its still heavy and I'm 28 and I think I'm getting lite headed

You should absolutely know your body more then you appear too, after all you are not a teen anymore, you are pushing 30. If you are bleeding that much and getting lightheaded bigtasty, then go the emerg and get checked out (have someone drive you) before you pass out and bleed to death.

Tick