What Causes Vaginal Spotting,bleeding And Breast Pain After Taking Levonelle?

I took Levonelle 3 weeks ago today a few days after my period finished and a few hours after unprotected sex with someone. I and had some spotting during the first 2 weeks, then 2 weeks to the day I started bleeding for nearly a week but it was much lighter than any period I have had before, Now today 3 weeks after I took the pill I am bleeding again and my breasts ache, I was also physically sick yesterday. Have taken 2 pregnancy tests both say negative. I am 43. How long it will it take for my hormones to return to normal. I want my body back? and will it make me have an early menopause? I have never been on the pill or taken hormones before.